Name: Keto Cheeseburger Casserole Recipe
Prep time: 15 min
Cook time: 15 min
Total time: 30 min
Cuisine: American
Ingredients: Olive oil spray, for greasing the baking dish; 2 tablespoons olive oil; 2 pounds extra-lean ground beef; 1 medium onion, finely chopped (about 6 ounces); 2 teaspoons Diamond Crystal kosher salt (see notes); 1/4 teaspoon black pepper; 1 tablespoon fresh garlic, minced; 1/4 cup mayonnaise; 1/4 cup unsweetened ketchup; 1 tablespoon mustard; 1 1/2 cups cheddar cheese, sharp, shredded and divided (about 6 ounces total)

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If you crave a hearty, flavor-packed dinner without all the carbs, this Keto Cheeseburger Casserole is going to make your weeknights so much more delicious. Imagine everything you love about a classic cheeseburger—melty cheddar, juicy beef, tangy ketchup and mustard—baked into a warm, bubbly casserole you can scoop right out of the pan. It’s fast enough for a busy weekday dinner, rich enough to be comfort food, and honestly, so craveable that even non-keto eaters will be sneaking seconds. You’re about to fall hard for this Keto Cheeseburger Casserole!

Keto Cheeseburger Casserole Recipe - Recipe Image

Ingredients You’ll Need

This recipe is a prime example of how simple ingredients can come together to create big, bold flavors. Each component brings something special to the dish, from the savory beef to the sharp cheddar and creamy sauce—so don’t skip a thing!

Olive oil spray: Helps prevent sticking and ensures the casserole comes out of the baking dish easily.
Olive oil: Adds depth and richness while helping to brown the beef and soften the onions to perfection.
Extra-lean ground beef: The star of the show, bringing tons of flavor and protein with less fat.
Onion (finely chopped): Adds sweetness and aromatic flavor that brings the whole casserole together.
Diamond Crystal kosher salt: Balances and enhances the savory notes—be sure to adjust if you use another brand or type.
Black pepper: Gives the casserole a mild heat and subtle brightness.
Fresh garlic (minced): Packs an aromatic punch that deepens the umami goodness.
Mayonnaise: Makes the casserole extra creamy and binds the other flavors.
Unsweetened ketchup: Delivers that classic burger tang without adding sugar or carbs.
Mustard: Brings a little zing and authentic cheeseburger flavor.
Cheddar (sharp, shredded): Melts into gooey perfection and gives every bite its signature cheesy pull.

How to Make Keto Cheeseburger Casserole

Step 1: Preheat and Prep

Start by preheating your oven to 400°F, and give your baking dish a quick spray with olive oil. This step keeps cleanup a breeze and ensures that every scoop of your Keto Cheeseburger Casserole comes out perfect.

Step 2: Brown the Beef and Onions

Heat your olive oil in a large skillet over medium-high for about two minutes, so it’s hot enough to sizzle. Toss in the ground beef and chopped onions, breaking up the meat as it cooks. You’ll want the beef browned and the onions soft, which should take about five minutes. The aroma in your kitchen will already start to resemble your favorite burger joint.

Step 3: Drain and Season

If you see extra liquid at the bottom of your skillet, simply drain it off—this keeps your casserole from becoming watery. Return the mixture to the pan and stir in the kosher salt, black pepper, and minced garlic. Let it cook for just one more minute so the garlic gets nice and fragrant.

Step 4: Mix in Sauces and Cheese

Turn off the heat. Now comes the magical part: add in your mayonnaise, unsweetened ketchup, mustard, and one cup of shredded cheddar cheese. Fold everything together so that the beef gets coated in that creamy, tangy sauce and gooey cheese. This mixture is the soulful heart of the Keto Cheeseburger Casserole.

Step 5: Assemble and Bake

Transfer the beef mixture to your prepared baking dish and sprinkle over the remaining half cup of cheddar cheese. Slide the dish into the oven and bake for about 15 minutes, until the cheese is melted and everything is heated through. If you like your cheese a little bubbly and golden, you can pop it under the broiler for 1-2 minutes—just be sure to keep an eye on it!

How to Serve Keto Cheeseburger Casserole

Garnishes

Finish your Keto Cheeseburger Casserole with a flourish! Try scattered diced pickles, fresh chopped parsley, or a few sliced green onions on top. A light sprinkle of sesame seeds adds a fun burger-inspired twist, and a swirl of extra mustard or keto-friendly ketchup makes it super inviting.

Side Dishes

Serve your casserole with simple sides that complement its comfort-food feel. A crisp green salad, roasted broccoli, or steamed green beans all add color and keep the meal balanced. If you’re missing that burger-and-fries spirit, whip up some baked turnip or zucchini fries!

Creative Ways to Present

Turn dinnertime into something special by serving your Keto Cheeseburger Casserole in individual ramekins, or pile generous scoops onto butter lettuce leaves for a low-carb “burger wrap” experience. You could even top each serving with a fried egg or sliced avocado for a brunch-style twist that keeps things fresh and exciting.

Make Ahead and Storage

Storing Leftovers

Leftovers are a lifesaver, and this casserole keeps beautifully for up to 3 or 4 days in an airtight container in the fridge. The flavors meld together even more, making day-two lunches a real treat!

Freezing

If you want to plan ahead, portion out servings and freeze them in individual containers for up to three months. This makes Keto Cheeseburger Casserole a stellar option for meal prep—thaw overnight in the fridge and you’re ready to go.

Reheating

For best results, reheat leftovers in the microwave at 50 percent power until warmed through. This keeps the casserole moist and prevents the cheese from becoming rubbery. If you prefer, you can warm it gently in the oven at 325°F, covered with foil to maintain that creamy texture.

FAQs

Can I substitute the ground beef with turkey or chicken?

Absolutely! Ground turkey (preferably thigh meat) or chicken thighs work well here. The casserole will taste a bit lighter, but it still delivers that cheeseburger flavor you crave. Avoid extra-lean or breast-only cuts as they tend to dry out.

What kind of ketchup should I use for Keto Cheeseburger Casserole?

Look for unsweetened or no-sugar-added ketchup, which is now widely available in most grocery stores. Regular ketchup has a surprising amount of sugar, so swapping it out is key to keeping the casserole keto-friendly.

Can I add vegetables to make this a complete meal?

Definitely! Adding riced cauliflower (1–2 cups) to the beef and onion mixture is a fantastic way to sneak in extra veggies while keeping the dish low-carb. Just sauté it in with the meat and onions, and maybe add a little more olive oil to keep things moist.

How can I make this casserole spicy?

Spice lovers can add a chopped jalapeño or a pinch of red pepper flakes while browning the beef and onions. Pepper jack cheese is also a fun substitute for some or all of the cheddar to give the casserole a bolder kick.

Is Keto Cheeseburger Casserole kid-friendly?

Kids usually adore this casserole! The flavors are super approachable and reminiscent of cheeseburgers they already love. If your crew is picky about onions, just chop them finely or sauté them well so their texture blends in seamlessly.

Final Thoughts

If you’re looking for a cozy, crowd-pleasing dinner or an easy way to meal prep lunches for the week, Keto Cheeseburger Casserole will quickly become your go-to recipe. With piles of cheesy goodness and classic burger charm, it’s a surefire hit. Give it a try—you might find yourself coming back for seconds (or even thirds)!