Low-Carb Waffle Burger With Crispy Zucchini Cheese Buns — Keto, 8g Net Carbs, Ready in 25 Minutes

I have eaten my share of low-carb burgers that arrived as a sad stack of meat and lettuce sitting in a pool of its own juices, held together by nothing except willpower and a toothpick. They are not satisfying. They do not feel like a burger. They feel like something was taken away.

This low-carb waffle burger is the opposite of that. The buns are hot, crispy-edged, cheesy waffles made from grated zucchini, carrot, and mozzarella — cooked until they are golden and firm enough to actually hold a loaded burger together without falling apart in your hands. There is a juicy beef patty with melted cheese. There are pickles and cold tomato and lettuce. There is a spicy, creamy sauce. The whole thing comes together in 25 minutes. It is a proper burger. It just happens to have 8 grams of net carbs instead of 40.

If you have spent time in low-carb cooking communities, you may already know these cheese-egg waffles by another name: chaffles. A chaffle — the term comes from combining cheese and waffle — became one of the most popular keto recipes of the last several years because the concept is simple and genuinely works. Adding grated zucchini and carrot to the standard chaffle formula makes the bun lighter, adds color and fiber, and gives it a texture closer to an actual bread bun than the plain cheese version. Every improvement here is deliberate.

If you are in the UK or Australia, zucchini is labeled courgette at the supermarket — the same vegetable, same recipe, same result. Ground beef is minced beef. A skillet is a frying pan. Everything else is identical.

Why This Recipe Works

Mozzarella is the right cheese for waffle buns specifically because of how it melts. Low-moisture, part-skim mozzarella — the shredded kind sold in bags — melts flat and crisps as it cools, which is exactly what you want a waffle bun to do. Cheddar melts greasier. Parmesan melts thinner. Mozzarella melts firm, holds the shape of the waffle grid, and gives you those crispy, lacy edges that make these buns feel like an upgrade rather than a substitute.

The egg is doing two things. It emulsifies the mixture, binding the grated vegetables and cheese into something cohesive enough to pour into a waffle maker and hold a shape. It also provides protein that sets during cooking and gives the waffle structural integrity. Without the egg, the mixture would spread, not hold.

Squeezing the water out of the zucchini is not optional and it is not a suggestion buried at the bottom of a tip box. It is the single most important step in the recipe. Zucchini is approximately 95 percent water. Grated zucchini that has not been squeezed will release that water into the hot waffle iron, creating steam that prevents crisping and leaves the bun wet and structurally useless. Squeeze until your hands ache. Then squeeze again.

The carrot is a deliberate addition rather than filler. It adds a tiny amount of natural sweetness that plays well against the sriracha in the sauce, and its lower water content compared to zucchini means it does not need pre-squeezing. It also adds color — a plain zucchini mozzarella waffle is pale; the carrot gives the bun a warm golden hue that looks more like a toasted bun than a science experiment.

Prep & Cooking

• Prep Time: 10 minutes
• Cook Time: 15 minutes
• Total Time: 25 minutes
• Servings: 1 burger

Ingredients

For the Waffle Buns

• 3 tablespoons / 35g grated zucchini, squeezed firmly dry — courgette in the UK and Australia; grated is the same as shredded
• 2 tablespoons / 20g grated carrot
• 2 tablespoons / 15g shredded low-moisture mozzarella — the pre-grated kind from a bag, not fresh mozzarella in water
• 1 large egg
• 1/4 teaspoon garlic powder
• Salt and black pepper to taste

For the Burger Patty

• 4 oz / 115g ground beef (80/20 fat ratio recommended) — minced beef in the UK and Australia; see fat ratio note below
• 1 slice cheese — cheddar, American, provolone, or any melt-friendly variety
• Salt and black pepper for seasoning

For the Assembly

• 1 to 2 lettuce leaves — iceberg for crunch, butter lettuce for tenderness
• 2 to 3 tomato slices
• 3 to 4 pickle slices — dill pickles or bread-and-butter depending on preference

For the Sauce

• 2 tablespoons / 30g plain full-fat Greek yogurt — Greek-style yogurt in UK and Australia; full-fat only
• 1 teaspoon sriracha hot sauce — or Tabasco, Frank's RedHot, or any chilli sauce you have

Ingredient Spotlight

• 80/20 Ground Beef: An 80/20 ground beef — 80 percent lean, 20 percent fat — will stay juicy in a 4-ounce patty cooked over high heat. A leaner beef in this size will cook through quickly and come out dry, which is especially noticeable when you are eating a single small patty with no bread to mask the texture.
• Low-Moisture Mozzarella: Fresh mozzarella — the white ball sold in water or brine — contains far too much liquid to work in a waffle bun. It will not crisp. It will make the waffle wet and dense and it will stick to the iron. Use the pre-shredded, low-moisture kind sold in bags.
• Full-Fat Greek Yogurt: Full-fat Greek yogurt for the sauce is non-negotiable if you want a sauce that holds on the waffle rather than immediately soaking in. Low-fat yogurt is too thin and too watery and will make the bottom waffle soggy within 90 seconds of assembly.

Equipment

A mini waffle maker is strongly preferred over a standard-sized waffle maker for this recipe. A standard waffle maker produces a bun that is approximately 7 to 8 inches across — far too large for a 4-ounce burger patty, and the mixture spreads too thin to cook into a sturdy bun. A mini waffle maker produces a round bun approximately 4 inches in diameter, which is the correct proportion for this patty size.

If you do not own any waffle maker, the waffle bun alternative is a small non-stick pan or well-seasoned cast iron skillet. Spoon the mixture into the hot greased pan, press it flat into a circle with a spatula, and cook over medium heat for 3 to 4 minutes per side, pressing down firmly with the spatula while it cooks to ensure even contact. The texture will be slightly less crispy than the waffle iron version but functionally identical.

A heavy skillet or cast iron pan for the burger patty gives better sear than a non-stick pan. The Maillard reaction — the browning that creates flavor — happens most aggressively on a very hot surface, and non-stick pans run cooler than stainless or cast iron.

Instructions

Step 1 — Grate and squeeze the zucchini

Grate the zucchini on the large holes of a box grater. Place the grated zucchini in the center of a clean kitchen towel, pull the corners together, and twist firmly over the sink until you are squeezing with both hands and no more liquid drips. Open the towel, and the zucchini should be noticeably drier, slightly clumped together, and reduced in volume. Measure the 3 tablespoons after squeezing, not before — you will likely need to start with slightly more grated zucchini to end up with 3 tablespoons of dry shreds.

Pro Tip: If you are using paper towels instead of a kitchen towel, use a thick stack — at least four layers — and press down hard and steadily rather than twisting. Twisting with paper towels tears them and leaves paper fragments in the mixture. Pressing works better with the thinner material.

Step 2 — Make the waffle batter

In a small bowl, combine the squeezed zucchini, grated carrot, shredded mozzarella, egg, garlic powder, salt, and black pepper. Mix with a fork until everything is evenly distributed and the egg has fully coated the vegetables and cheese. The mixture should look thick and slightly loose — it will firm up in the waffle iron. If it looks very wet or runny, the zucchini was not squeezed enough. You can add an additional teaspoon of grated mozzarella to absorb the excess moisture.

Step 3 — Preheat the waffle maker and cook the buns

Preheat the mini waffle maker according to the manufacturer's instructions. Most mini waffle makers are ready in 2 to 3 minutes — the indicator light changes when it is up to temperature. If the manual says to grease it, use a very light spray of cooking oil or a small amount of butter on a paper towel. Do not over-grease — excess oil will pool and make the edges greasy rather than crispy.

Spoon exactly half the mixture into the center of the waffle iron and close the lid. Do not open the lid for at least 3 minutes. Opening early releases the steam that is helping the egg set, and the waffle will stick and tear. At 3 minutes, try lifting the lid slightly. If there is any resistance, wait another minute. A properly cooked waffle will release cleanly without pulling or sticking. Cook for 3 to 5 minutes total, until the edges are visibly golden and crispy and the waffle feels firm when you press the top lightly. Transfer to a plate and cook the second waffle from the remaining mixture.

Pro Tip: The second waffle almost always cooks faster than the first because the iron is now fully up to temperature. Watch it from the 2-minute mark to avoid overcooking.

Step 4 — Cook the burger patty

While the second waffle cooks, season the ground beef patty on both sides with salt and black pepper. Heat a heavy skillet or frying pan over medium-high heat until it is genuinely hot — a drop of water flicked in should evaporate immediately on contact. If it sits there and slowly evaporates, the pan is not hot enough. Add the patty and cook without moving it for 3 minutes. Do not press it with a spatula — pressing squeezes out the juices that make a small patty like this worth eating. Flip once. Cook for another 2 to 3 minutes depending on your preferred doneness. In the final 60 seconds of cooking, lay the cheese slice on top of the patty and cover the pan with a lid or a heatproof plate to trap steam and melt the cheese quickly and evenly.

Step 5 — Make the sauce

In a small bowl, stir together the Greek yogurt and sriracha until fully combined. Taste it. If you want more heat, add another 1/2 teaspoon of sriracha. If you want it milder, add another teaspoon of yogurt. The sauce should be thick enough to sit on the waffle without running — not pourable, more like a spreadable consistency.

Step 6 — Assemble immediately

Place one waffle on the plate. Spread half the sauce across the surface. Layer on the lettuce leaves, tomato slices, the cooked patty with melted cheese, and the pickle slices. Spread the remaining sauce on the underside of the second waffle and place it sauce-side down on top of the stack. Press gently to seat everything together. Serve immediately.

Easy Swaps

• What is the best cheese for waffle burger buns? Mozzarella is the best choice for the waffle bun itself because it melts firm and crisps cleanly without going greasy. Cheddar can be substituted and produces a stronger flavor and slightly denser texture.
• Can I use a protein other than beef? Ground turkey, ground chicken, and ground lamb all work. Ground turkey and chicken are leaner and will cook slightly faster — pull them at the 3-minute mark per side.
• What can I use instead of sriracha? Frank's RedHot Sauce is a direct swap. Tabasco produces a sharper, thinner heat and works well at half the quantity. Harissa paste gives a smoky, complex North African heat.

Storage & Reheating

• Waffle buns: Store cooked buns in an airtight container in the refrigerator for up to 3 days. Keep them separate from any sauce, lettuce, or tomato. To restore the exterior texture, reheat in a toaster oven at 375°F (190°C) for 5 to 6 minutes, or in an air fryer at 350°F (175°C) for 3 to 4 minutes.
• Burger patty: Store cooked patties separately in the refrigerator for up to 3 days. Reheat in a skillet over medium heat for 1 to 2 minutes per side. Do not reheat in the microwave.
• Sauce: Store in a sealed container in the refrigerator for up to 3 days. Stir before using.
• Freezer (Waffle buns only): Cool cooked buns completely, freeze flat until solid, then stack with parchment between each bun and store in a freezer bag for up to 2 months. Reheat directly from frozen in a toaster oven at 375°F (190°C) for 6 to 8 minutes.

Serving Ideas

• A cucumber salad dressed with rice vinegar, sesame oil, and a pinch of red pepper flakes.
• Roasted broccoli florets cooked at 425°F (220°C) for 20 minutes with olive oil, salt, and a squeeze of lemon.
• Crispy baked zucchini slices brushed with olive oil and seasoned with garlic powder and Parmesan.
• Simple side salad of arugula (rocket in UK/AU), cherry tomatoes, and lemon olive oil dressing.

Nutrition (Per Serving)

• Calories: 309
• Protein: 13g
• Carbohydrates: 8g
• Fat: 22g

Recipe FAQs