Low Carb Big Mac Casserole – Cheesy, Beefy & Bun-Free!

May 19, 2026

If you are craving the iconic flavors of your favorite fast-food burger but want to stick to a healthy, low-carb lifestyle, this Low Carb Big Mac Casserole is the ultimate solution. Packed with savory ground beef, melted cheese, tangy pickles, and a flawless sugar-free copycat special sauce, this dish delivers all the comfort food satisfaction without the high-carb guilt.

It’s an easy keto dinner recipe that the whole family will love, making it a perfect addition to your weekly low-carb meal prep rotation.

🛒 Ingredients You’ll Need

Simple, wholesome ingredients come together to recreate a fast-food classic right in your kitchen.

For the Beef Layer

1½ lb (680 g) Ground Beef: Lean or regular both work well.
1 Small Onion: Finely diced for that authentic burger crunch.
2 Cloves Garlic: Minced for a rich savory base.
1 tsp Salt & ½ tsp Black Pepper: Simple seasonings to let the beef flavor shine.

For the Copycat Special Sauce

½ cup Mayonnaise: The creamy base for the dressing.
2 tbsp Sugar-Free Ketchup: Keeps the carbs low while adding classic tang.
1 tbsp Yellow Mustard: Provides a sharp, zesty kick.
1 tbsp Dill Pickle Relish: Ensure it's no-sugar-added to keep it keto-friendly.
1 tsp Apple Cider Vinegar: Adds the perfect bright acidity.
½ tsp Paprika: For warmth and a touch of color.

For the Cheesy Topping & Garnish

1½ cups Shredded Cheddar & ½ cup Shredded Mozzarella: A blend for maximum melt and gooey texture.
½ cup Chopped Dill Pickles: Essential for that signature burger bite.
1 cup Shredded Lettuce: Added right before serving for freshness.
Sesame Seeds (Optional): A fun nod to the classic sesame seed bun!

👩‍🍳 Step-by-Step Directions

1. Prep the Oven

Preheat your oven to 375°F (190°C) and lightly grease a 9x13-inch baking dish.

2. Brown the Beef

In a large skillet over medium heat, cook the ground beef with the diced onion and minced garlic until the meat is completely browned. Drain off any excess fat, then season the mixture with the salt and black pepper.

3. Whisk the Sauce

While the beef cooks, prepare the signature burger sauce. In a small bowl, thoroughly whisk together the mayonnaise, sugar-free ketchup, yellow mustard, dill pickle relish, apple cider vinegar, and paprika until smooth.

4. Assemble the Casserole

Spread the seasoned cooked beef evenly across the bottom of your prepared baking dish. Pour the creamy special sauce over the beef layer and use a spatula to spread it in an even layer.

5. Bake to Melted Perfection

Top the sauce layer generously with the shredded cheddar and mozzarella cheeses. Bake for 15–20 minutes until the cheese is melted, golden, and bubbly around the edges.

6. Garnish and Serve

Remove the casserole from the oven and let it rest for 5 minutes. Right before serving, scatter the chopped pickles and shredded lettuce over the hot cheese, and finish with a sprinkle of sesame seeds if desired.