Keto Cheeseburger Casserole

Name: Keto Cheeseburger Casserole
Prep time: 15 min
Cook time: 15 min
Total time: 30 min
Ingredients: Olive oil spray (for the baking dish); 2 tablespoons olive oil; 2 pounds extra-lean ground beef; 1 medium onion (finely chopped; 6 ounces); 2 teaspoons Diamond Crystal kosher salt (see notes below); 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 cup cheddar (sharp, shredded, divided; 6 ounces total)

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This easy 30-minute keto cheeseburger casserole is hearty, filling, and an excellent alternative to a classic cheeseburger. You can make it as written and serve it with a side of veggies, or mix in veggies such as cauliflower rice or spinach and turn it into a complete meal.

Keto cheeseburger casserole is served in a baking dish.

Casseroles are so easy. You place a few ingredients in a baking dish, put it in the oven, and dinner is ready 30-60 minutes later! This cheeseburger casserole is delicious in a delightfully non-gourmet sort of way. Grownups and kids alike enjoy it. Like most casseroles, it's a forgiving and flexible recipe, so you can experiment with different mix-ins and spices.

Ingredients

You'll only need a few simple ingredients to make this recipe. 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. Other options include avocado oil and ghee.
Extra-lean ground beef: I prefer to use extra-lean ground beef (93% lean) because I drain the rendered fat anyway. However, using lean ground beef (85% lean) is OK if that's what you have. As you can see in the photo above, I sometimes use it.
Onion and garlic. Sometimes, when I'm lazy, I sub onion and garlic powders - two teaspoons of each. But it's not as good.
Kosher salt and black pepper: I use Diamond Crystal Kosher Salt.
Mayonnaise: I prefer mayonnaise made with avocado oil.
Ketchup: I use unsweetened ketchup.
Mustard: I usually like Dijon mustard. But in this recipe, yellow mustard works too.
Shredded cheddar: I like to use sharp or extra-sharp cheddar. It greatly enhances the flavor of this casserole.

Variations

The best thing about this recipe is how simple it is to make. But if you'd like to experiment a little, here are a few ideas for you:

Add crumbled cooked bacon. I love the flavor it adds.
You can make this recipe with ground chicken or turkey thighs. It won't be the same, but it's still good. I recommend using ground chicken thighs, not chicken breast, which is too lean.
Add your favorite spices, even if they're not classic cheeseburger seasonings. Smoked paprika and chili powder are excellent in this recipe. You can add a teaspoon of each.
Sometimes, I mix sliced pickled jalapenos into the beef mixture before baking it.

Instructions

The detailed instructions for making this casserole are included in the recipe card below. Here's an overview of the steps:

You start by cooking ground beef and onion in olive oil. Drain and add seasonings: Garlic, salt, and black pepper.

Adding salt, pepper, and garlic to the ground beef mixture.

Off heat, stir in condiments: Mayo, ketchup, and mustard. Then, stir in shredded cheese.

The last step is to transfer the mixture to a greased baking dish and sprinkle it with more cheese.

Cheeseburger casserole mixture is ready for baking in the baking dish.

Bake the casserole for about 15 minutes at 400°F, then serve!

Expert Tip

If you'd like to turn this casserole into a complete meal, add 1-2 cups of uncooked riced cauliflower to the ground beef/onion mixture and cook everything together. If you do, increase the olive oil by 1-2 tablespoons.

Recipe FAQs

What type of beef do you use in a cheeseburger casserole?

I use extra lean ground beef (93% lean). I prefer lean ground beef (85% lean) in most of my recipes, but when I cook it for a casserole, I drain the fat anyway.

Can I add vegetables?

Absolutely! One option mentioned above is to add riced cauliflower
to the beef/onion mixture.

You can also add two cups (about 2 ounces) of raw baby spinach leaves to the beef mixture when it's done cooking. Add the spinach right before adding the seasonings and mix it in until it wilts very slightly. Don't overcook it.

Can you make a casserole without a starchy ingredient?

Yes! A classic casserole contains protein (meat, poultry), starch (rice, potatoes), vegetables, sauce, and cheese.

But one of the best things about casseroles is that they are flexible and forgiving, so you can adapt them to your needs and the ingredients you have on hand. Made as written, this casserole contains just protein, sauce, and cheese and is delicious.

Serving Suggestions

This cheeseburger casserole is very rich. To balance out its richness, I recommend skipping the starches and serving it with a side veggie. A few options I like:

Storing Leftovers

You can keep the leftovers in an airtight container in the fridge for 3-4 days. Reheat them gently in the microwave at 50% power. You can also freeze individual servings for up to three months.