Keto Big Mac Casserole – A Low-Carb Take on a Fast-Food Favorite

If you crave the classic flavors of a Big Mac but want to keep things low-carb, this keto Big Mac casserole hits the spot. It packs in seasoned ground beef, melty cheese, and a tangy “special sauce,” all layered with crisp pickles and lettuce for that familiar taste. It’s easy enough for weeknights and satisfying enough for meal prep.

No buns, no fuss—just savory, creamy, crunchy goodness in every bite. This is comfort food without the carb crash.

Save

Keto Big Mac Casserole - A Low-Carb Take on a Fast-Food Favorite

Print Recipe Pin Recipe

Prep Time 15 minutes mins

Cook Time 30 minutes mins

Total Time 45 minutes mins

Servings: 6 servings

Ingredients Method

Ingredients

  

• 1.5 pounds ground beef (80/20 or 85/15)
• 1 small onion, finely diced
• 2 cloves garlic, minced
• 1 teaspoon kosher salt, plus more to taste
• 1/2 teaspoon black pepper
• 1 teaspoon smoked paprika (optional but recommended)
• 1 teaspoon onion powder
• 1 teaspoon mustard powder
• 1 tablespoon Worcestershire sauce (check for low sugar)
• 1/4 cup sugar-free ketchup
• 2 tablespoons dill pickle relish (no sugar added) or finely chopped dill pickles
• 1/2 cup mayonnaise
• 1/4 cup sour cream or plain Greek yogurt (low carb)
• 2 teaspoons yellow mustard
• 1 tablespoon apple cider vinegar
• 1–2 teaspoons granular keto sweetener, to taste (optional, for that classic sauce vibe)
• 8 ounces shredded cheddar cheese (or a mix of cheddar and Monterey Jack)
• 2 large eggs
• 1/4 cup heavy cream
• 1 cup shredded iceberg or romaine lettuce (for topping)
• 1/2 cup sliced dill pickles (for topping)
• Sesame seeds, for garnish (optional but fun)
• Olive oil or avocado oil, as needed for sautéing

Method

 

1. Preheat and prep: Heat the oven to 350°F (175°C). Lightly grease a 9x13-inch casserole dish.
2. Cook the beef: Warm a large skillet over medium-high heat with a splash of oil. Add the onion and cook 3–4 minutes until softened. Stir in the garlic for 30 seconds.
3. Brown and season: Add ground beef, breaking it apart as it cooks. Season with salt, pepper, smoked paprika, onion powder, and mustard powder. Cook until no longer pink and most moisture evaporates, about 6–8 minutes.
4. Add umami: Stir in Worcestershire sauce and sugar-free ketchup. Let it simmer 1–2 minutes to thicken slightly. Taste and adjust salt and pepper.
5. Make the “special sauce” base: In a bowl, whisk mayonnaise, sour cream, yellow mustard, apple cider vinegar, pickle relish, and sweetener (if using). Reserve 1/3 cup of this sauce for topping after baking.
6. Bind the casserole: In a small bowl, whisk eggs and heavy cream. Stir the remaining special sauce into the beef mixture, then pour in the egg-cream blend. Mix until combined.
7. Assemble: Spread the beef mixture evenly in the casserole dish. Sprinkle shredded cheese over the top.
8. Bake: Bake for 18–22 minutes, until the cheese is melted and bubbly and the edges are set.
9. Rest and top: Let the casserole rest 5–10 minutes. Drizzle with the reserved special sauce, then add shredded lettuce, sliced pickles, and a light sprinkle of sesame seeds.
10. Serve: Slice into squares and serve warm. Add extra pickles or a dash of hot sauce if you like some heat.

What Makes This Recipe So Good

Save

• All the flavor, fewer carbs: You get the burger, cheese, pickles, and sauce experience without the bun.
• One-pan ease: Everything bakes in a casserole dish, so cleanup is simple and fast.
• Meal-prep friendly: It reheats well and stays tasty for days, making it perfect for batch cooking.
• Balanced textures: Creamy sauce, juicy beef, melty cheese, and crunchy toppings make each serving feel complete.
• Customizable: Adjust the heat, the cheese, or the toppings to match your taste and macros.

Ingredients

• 1.5 pounds ground beef (80/20 or 85/15)
• 1 small onion, finely diced
• 2 cloves garlic, minced
• 1 teaspoon kosher salt, plus more to taste
• 1/2 teaspoon black pepper
• 1 teaspoon smoked paprika (optional but recommended)
• 1 teaspoon onion powder
• 1 teaspoon mustard powder
• 1 tablespoon Worcestershire sauce (check for low sugar)
• 1/4 cup sugar-free ketchup
• 2 tablespoons dill pickle relish (no sugar added) or finely chopped dill pickles
• 1/2 cup mayonnaise
• 1/4 cup sour cream or plain Greek yogurt (low carb)
• 2 teaspoons yellow mustard
• 1 tablespoon apple cider vinegar
• 1–2 teaspoons granular keto sweetener, to taste (optional, for that classic sauce vibe)
• 8 ounces shredded cheddar cheese (or a mix of cheddar and Monterey Jack)
• 2 large eggs
• 1/4 cup heavy cream
• 1 cup shredded iceberg or romaine lettuce (for topping)
• 1/2 cup sliced dill pickles (for topping)
• Sesame seeds, for garnish (optional but fun)
• Olive oil or avocado oil, as needed for sautéing

Instructions

Save

1. Preheat and prep: Heat the oven to 350°F (175°C). Lightly grease a 9×13-inch casserole dish.
2. Cook the beef: Warm a large skillet over medium-high heat with a splash of oil.

   Add the onion and cook 3–4 minutes until softened. Stir in the garlic for 30 seconds.

3. Brown and season: Add ground beef, breaking it apart as it cooks. Season with salt, pepper, smoked paprika, onion powder, and mustard powder.

   Cook until no longer pink and most moisture evaporates, about 6–8 minutes.

4. Add umami: Stir in Worcestershire sauce and sugar-free ketchup. Let it simmer 1–2 minutes to thicken slightly. Taste and adjust salt and pepper.
5. Make the “special sauce” base: In a bowl, whisk mayonnaise, sour cream, yellow mustard, apple cider vinegar, pickle relish, and sweetener (if using).

   Reserve 1/3 cup of this sauce for topping after baking.

6. Bind the casserole: In a small bowl, whisk eggs and heavy cream. Stir the remaining special sauce into the beef mixture, then pour in the egg-cream blend. Mix until combined.
7. Assemble: Spread the beef mixture evenly in the casserole dish.

   Sprinkle shredded cheese over the top.

8. Bake: Bake for 18–22 minutes, until the cheese is melted and bubbly and the edges are set.
9. Rest and top: Let the casserole rest 5–10 minutes. Drizzle with the reserved special sauce, then add shredded lettuce, sliced pickles, and a light sprinkle of sesame seeds.
10. Serve: Slice into squares and serve warm. Add extra pickles or a dash of hot sauce if you like some heat.

How to Store

• Refrigerator: Store leftovers in an airtight container for up to 4 days.

  Keep the lettuce and pickles separate and add them fresh when serving.

• Freezer: Freeze the baked, untopped casserole tightly wrapped for up to 2 months. Thaw overnight in the fridge before reheating, then add toppings.
• Reheat: Warm slices in a 325°F oven for 10–15 minutes or microwave in short intervals until heated through. Add fresh lettuce and pickles after reheating.

Save

Benefits of This Recipe

• Keto-friendly: Low in carbs and high in fat, it fits well within a ketogenic diet.
• Protein-rich: Ground beef provides steady, satisfying protein to keep you full.
• Family-approved: Familiar flavors make this an easy sell, even for picky eaters.
• Budget-friendly: Uses accessible ingredients and stretches into multiple meals.
• Flexible macros: You can tweak cheese, sauce, and toppings to match your goals.

Pitfalls to Watch Out For

• Hidden sugars: Many ketchups, relishes, and Worcestershire sauces contain sugar.

  Choose sugar-free or low-sugar versions.

• Greasy casserole: If using higher-fat beef, drain excess grease after browning to avoid a soggy texture.
• Overbaking: Too long in the oven can dry out the beef. Pull it when the cheese melts and the center is just set.
• Soggy toppings: Add lettuce and pickles right before serving. Don’t bake them.
• Too tangy or too sweet sauce: Adjust vinegar and sweetener gradually.

  Taste as you go.

Recipe Variations

• Cheese swap: Try American cheese slices for classic fast-food vibes, or use a blend of cheddar and pepper jack for heat.
• Bacon big mac: Fold in cooked, chopped bacon for extra richness and smoky flavor.
• Pickled jalapeño: Add a mild kick with sliced pickled jalapeños on top before serving.
• Dill forward: Increase fresh or dried dill in the sauce for a sharper pickle note.
• Extra veg: Stir in finely chopped mushrooms or riced cauliflower for more volume with minimal carbs. Sauté first to release moisture.
• Dairy-light: Use less cheese and swap sour cream for more mayo to reduce lactose. Choose lactose-free cheese if needed.
• Turkey version: Sub ground turkey, add 1 tablespoon olive oil, and bump up spices for flavor.

FAQ

Is this casserole really low carb?

Yes.

Without the bun and with sugar-free condiments, it’s very low in carbs. Most of the carbs come from the sauce, onions, and toppings, which you can adjust.

Can I make it ahead?

Absolutely. Assemble the beef layer and cheese, then cover and chill up to 24 hours.

Bake when ready, then add toppings and sauce.

What goes well with this casserole?

A simple side salad, roasted broccoli, or green beans keeps it light and keto-friendly. You can also add a side of cauliflower mash for extra comfort.

How do I keep the sauce tasting like a Big Mac?

Use dill pickles or dill relish, yellow mustard, a touch of vinegar, and a small amount of keto sweetener. Taste and balance salt, tang, and a hint of sweetness.

Can I skip the eggs?

You can, but the eggs help bind the casserole so it slices cleanly.

If skipping, reduce heavy cream to 2 tablespoons and bake until set.

What if I don’t have sugar-free ketchup?

Use tomato paste thinned with a little water and season with salt, vinegar, and a pinch of keto sweetener. Start small and adjust to taste.

How do I make it spicier?

Add crushed red pepper, cayenne, or hot sauce to the beef mixture. Pepper jack cheese or pickled jalapeños on top also work well.

Can I use shredded lettuce in the bake?

It’s best added after baking.

Lettuce turns limp and watery in the oven, which can affect texture.

What’s the best ground beef for this?

An 80/20 blend gives a juicy result. If you prefer leaner, go 90/10 and add a tablespoon of oil plus an extra splash of heavy cream for richness.

Final Thoughts

This keto Big Mac casserole brings familiar, nostalgic flavors to your table with a low-carb twist. It’s easy to make, easy to reheat, and endlessly customizable.

Whether you’re meal prepping for the week or feeding a crowd, it delivers comfort and convenience without straying from your goals. Keep the toppings fresh, taste your sauce as you go, and enjoy a hearty, satisfying dish that feels like fast food—minus the bun.