Keto Cheeseburger Casserole
This easy keto cheeseburger casserole delivers all the flavor of a classic burger without the bun. Ready in 30 minutes with simple ingredients, it's perfect for busy weeknights.
Ingredients
- 2 tablespoons olive oil good quality
- 2 pounds extra-lean ground beef 93% lean
- 1 medium onion 6 ounces, chopped fine
- 2 teaspoons kosher salt Diamond Crystal brand; use 1 tsp for table salt
- 1/4 teaspoon black pepper fresh ground preferred
- 1 tablespoon garlic fresh or jarred
- 1/4 cup mayonnaise
- 1/4 cup unsweetened ketchup
- 1 tablespoon mustard yellow or Dijon
- 1.5 cups sharp cheddar cheese 6 oz, shredded, divided
Instructions
- Preheat your oven to 400°F. Grease a 2-quart baking dish with cooking spray or butter.
- Pour olive oil into a large skillet over medium-high heat. Let the oil heat for about 2 minutes until hot.
- Add ground beef and chopped onions to the hot skillet. Break up the meat with a wooden spoon and stir occasionally. Cook for about 5 minutes until the beef is fully browned and onions are soft.
- Drain any excess liquid from the skillet by tilting the pan and using your spoon to hold back the meat.
- Add salt, pepper, and garlic to the beef mixture. Stir together and cook for 1 more minute.
- Turn off the heat. Add mayo, ketchup, and mustard to the beef. Mix until smooth and creamy.
- Add 1 cup of shredded cheddar cheese to the beef mixture (reserve remaining 1/2 cup for topping). Stir until the cheese melts into the mixture.
- Transfer the beef mixture to the prepared baking dish and spread evenly. Sprinkle the reserved cheese on top, covering the entire surface.
- Bake for 15 minutes until the cheese is completely melted and golden brown in spots. For extra-crispy cheese, broil for 1-2 minutes, watching carefully.
- Let the casserole rest for 5 minutes before serving.
Notes
Storage: Store leftovers in an airtight container for 3-4 days in the fridge. For freezing, use individual portions in meal prep containers for up to 3 months.
Reheating: Microwave at 50% power to prevent rubbery edges, or reheat in a 300°F oven covered with foil.
Make Ahead: Prepare the beef mixture completely and refrigerate for up to 24 hours. Add the top cheese layer and bake when ready, adding 5 extra minutes to cooking time.
Variations: Add 1-2 cups riced cauliflower, baby spinach, or top with crispy bacon. Use ground turkey or chicken (dark meat) as protein alternatives.