Ingredients
For the Casserole
- 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
For the Sauce & Topping
- 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)
Instructions
- Preheat Oven and Prepare Baking Dish: Preheat your oven to 400°F (200°C). Spray a 2-quart baking dish with olive oil to prevent sticking.
- Brown Beef and Onions: Heat the olive oil in a large skillet over medium-high heat for about 2 minutes. Add the ground beef and chopped onion. Cook, breaking up the meat with a spoon, until the beef is browned and the onion is soft, about 5 minutes.
- Drain and Season: If there is liquid in the skillet, carefully drain it and return the mixture to the skillet. Stir in the kosher salt, black pepper, and minced garlic. Cook for 1 additional minute, stirring constantly.
- Add Sauce and Cheese: Turn off the heat. Mix in the mayonnaise, unsweetened ketchup, mustard, and 1 cup of the shredded cheddar cheese, stirring until the mixture is well combined.
- Assemble Casserole: Transfer the beef mixture to the prepared baking dish. Sprinkle the remaining 1/2 cup cheddar cheese evenly over the top.
- Bake or Broil: Bake in the preheated oven until the cheese is melted and the casserole is heated through, about 15 minutes. Alternatively, if using a broiler-safe dish, broil 6 inches below the element for 1–2 minutes until bubbly and golden. Serve hot.
Notes
- To make it a complete meal, stir in 1–2 cups of uncooked riced cauliflower with the beef and onion, increasing olive oil by 1–2 tablespoons. Cook together before adding sauce.
- If using a different salt brand (not Diamond Crystal), reduce the amount by half.
- Can substitute ground chicken or turkey thighs instead of beef, but avoid chicken breast as it’s too lean.
- Store leftovers in an airtight container in the refrigerator for 3–4 days. Reheat gently in the microwave at 50% power or freeze individual portions for up to three months.
- Prep Time: 15 minutes
- Cook Time: 15 minutes
- Category: Main-course
- Method: Baking
- Cuisine: American
- Diet: Gluten Free
Nutrition
- Serving Size: 1/6 of casserole
- Calories: 458 kcal
- Sugar: 2g
- Sodium: 771mg
- Fat: 31g
- Saturated Fat: 7g
- Unsaturated Fat: 24g
- Trans Fat: 0g
- Carbohydrates: 4g
- Fiber: 0g
- Protein: 38g
- Cholesterol: 0mg