This easy keto cheeseburger casserole is hearty and filling and makes a wonderful low carb alternative to a cheeseburger. You won’t miss the bun!

This casserole is delicious, in a delightfully non-gourmet sort of way. Grownups and kids alike always enjoy it. And the younger one – the Picky Eater- often asks for seconds!
You can make it as written, you can vary the spices you use, and you can add veggies. Like most casseroles, it’s a very forgiving and flexible recipe.
The ingredients you’ll need
You’ll only need a few simple ingredients to make this tasty keto cheeseburger casserole. The exact measurements are included in the recipe card below. Here’s an overview of what you’ll need:
Olive oil: My favorite oil to cook with! It’s so flavorful. But if you’re unsure about cooking with olive oil, you can use avocado oil instead. It has a higher smoke point.
Extra-lean ground beef: I prefer to use leaner beef here because I end up draining the rendered fat anyway.
Onion and garlic. Sometimes when I’m feeling extra lazy I sub onion and garlic powders… but it’s not the same. So I try not to be lazy!
Kosher salt and black pepper: If using fine salt instead of kosher salt, reduce the amount you use by half.
Mayonnaise: I prefer mayonnaise made with avocado oil to mayo made with other types of vegetable oils.
Unsweetened ketchup. Regular ketchup is quite sugary. You can find unsweetened ketchup at Whole Foods and on Amazon.
Mustard: I usually like Dijon mustard. It’s creamier and less vinegary than yellow mustard. But in this particular recipe, yellow mustard works too.
Shredded cheddar: I like to use sharp or even extra-sharp cheddar. It really enhances the flavor of this dish.
How to make keto cheeseburger casserole
This casserole is a wonderful option if you follow a keto or a low carb diet. You get all the wonderful flavors of a cheeseburger, without the soggy, spongy bun. Really, who needs a bun anyway? 😉
Scroll down to the recipe card for the detailed instructions. The basic steps are super easy:
- Start by cooking the beef and onion in olive oil.
- Add the garlic, salt, and black pepper.
- Off heat, stir in the mayo, ketchup, mustard, and half the cheese.
- Transfer the mixture to a greased baking dish and sprinkle with the remaining cheese. Bake for about 15 minutes at 400°F.

What beef to use
I use extra lean ground beef (93% lean). I’ve got nothing against lean ground beef (85% lean), but when I cook it for a casserole I end up draining the fat anyway. So it makes more sense to use leaner meat that doesn’t require much draining.
You can add veggies for a complete meal
I really like casseroles. They’re just so EASY. You place a few ingredients in the casserole dish, place it in the oven, and 30-60 minutes later, dinner is ready!
If you’d like to turn this casserole into a complete meal, you can add 1-2 cups of uncooked riced cauliflower to the meat and onion and cook everything together. You might need to increase the olive oil a little if you do.
How to serve keto cheeseburger casserole
To balance out the richness of this dish, I definitely recommend skipping the starches and serving it with a side veggie, such as simple steamed green beans, roasted asparagus or a green salad.
What about leftovers?
You can keep the leftovers in the fridge, in an airtight container, for 3-4 days. Reheat them gently, in the microwave, on 50% power. You can also successfully freeze individual servings for up to three months.
Reviews of this recipe
Pinterest users seem to like this recipe a lot. Here are a few of their comments:
- Easy to make. Came out delicious. I used ground turkey instead of beef.
- This was so delicious! I ate it with some salsa on the side and yum yum yum!
- Easy to make and everyone thought the keto cheeseburger casserole was delicious!
- Followed this recipe to a T and it turned out great! I will definitely make it again.
More ground beef recipes that you might enjoy
I have several that I really like. You should definitely try this very flavorful ground beef meat pie! And these baked hamburgers are the easiest recipe I have ever found to make burgers.
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Keto Cheeseburger Casserole
INGREDIENTS
- Olive oil spray for the baking dish
- 2 tablespoons olive oil
- 2 lb. extra lean ground beef
- 1 medium onion finely chopped (6 oz)
- 2 teaspoons Diamond Crystal kosher salt or 1 teaspoon fine salt
- 1/4 teaspoon black pepper
- 1 tablespoon minced fresh garlic
- 1/4 cup avocado oil mayonnaise
- 1/4 cup unsweetened ketchup
- 1 tablespoon mustard
- 1 1/2 cup shredded sharp cheddar divided (6 oz)
INSTRUCTIONS
- Preheat oven to 400 degrees F. Spray a 2-quart baking dish with olive oil.
- Heat the olive oil in a large skillet over medium-high heat, about 2 minutes. Add the beef and the onions. Cook, stirring to break up the beef, until the meat is browned and the onion is soft, about 5 minutes.
- If there are liquids at the bottom of the skillet, drain the mixture and return it to the skillet.
- Stir in the kosher salt, black pepper, and garlic. Cook, stirring, 1 more minute.
- Turn the heat off. Stir in the mayonnaise, unsweetened ketchup, mustard, and 1 cup cheddar.
- Transfer the mixture to the prepared baking dish. Sprinkle with the remaining cheese.
- Bake until the cheese is melted and the casserole is heated through, about 15 minutes. Or, if your baking dish is broiler-safe, broil the casserole 6 inches below the heating element (not directly below) until cheese is melted, 1-2 minutes.
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Vered DeLeeuw, LL.M., CNC, has been following a low-carb real-food diet and blogging about it since 2011. She's a Certified Nutrition Coach (NASM-CNC), has taken courses at the Harvard School of Public Health, and has earned a Nutrition and Healthy Living Certificate from Cornell University. Her work has appeared in several major media outlets, including Healthline, HuffPost, Today, Women's Health, Shape, Reader's Digest, and Better Homes and Gardens.