Loaded Cheeseburger Casserole with Caramelized Onions

By , Test Kitchen Director · Reviewed by AislePrompt Editorial · ·

A hearty casserole packed with ground beef, caramelized onions, and creamy cheese sauce for a satisfying keto meal. This american-inspired keto (low-carb) ready in about 55 minutes pairs ground beef, medium yellow onion, olive oil for a weeknight-friendly dinner that comes together with one pan and minimal cleanup. Each serving lands at about 550 calories and feeds 4, so it slots cleanly into a weekly meal plan and pairs well with a quick salad or grain on the side. Tap "Plan a meal with the AI" below to drop this recipe into your week and send the ingredients straight to Instacart. Nutrition values are approximate, calculated from USDA FoodData Central (fdc.nal.usda.gov) — verify against ingredient labels for any health-driven dietary plan.

Prep: 20 min Cook: 35 min Serves 4 American cuisine 550 cal/serving
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Ingredients

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Instructions

  1. Step 1: Heat 1 tbsp olive oil in a skillet over medium-high heat. Add 1 lb ground beef and cook, breaking it up, until browned (6-7 minutes). Drain excess fat.
  2. Step 2: Add 1 cup finely diced yellow onion to the skillet. Cook for 8 minutes until golden and caramelized, stirring occasionally.
  3. Step 3: Stir in 1/2 cup keto tomato sauce, 1/4 tsp garlic powder, 1/4 tsp onion powder, 1/4 tsp salt, and 1/8 tsp black pepper. Simmer for 5 minutes until thickened.
  4. Step 4: Transfer mixture to a 9x13-inch baking dish. Top with 1/4 cup cheddar, 1/4 cup mozzarella, and 1/4 cup sour cream.
  5. Step 5: Bake at 375°F for 20 minutes until bubbly and cheese is melted.

Frequently asked questions

How long does Loaded Cheeseburger Casserole with Caramelized Onions take to make?

Total time is about 55 minutes (20 min prep + 35 min cook). Most home cooks find this fits comfortably into a weeknight; double the batch on Sunday for two dinners.

How do I store leftover Loaded Cheeseburger Casserole with Caramelized Onions?

Cool to room temperature within 2 hours, then store in an airtight container in the fridge for up to 4 days. Reheat covered in a 350°F oven for 10-12 minutes, or microwave at 70% power in 60-second bursts to keep ground beef from drying out.

Can I substitute ingredients in Loaded Cheeseburger Casserole with Caramelized Onions?

Yes — most ingredients in this recipe have flexible swaps. For oil, use any neutral high-smoke-point oil (avocado, grapeseed, refined coconut). For aromatics, dried herbs at ⅓ the volume of fresh work in a pinch. The full ingredient list is shoppable on Instacart so you can see substitutes in real time.

How do I scale Loaded Cheeseburger Casserole with Caramelized Onions for a different number of people?

The recipe is written for 4 servings. Multiply each ingredient by (your serving target / 4). Cook time stays roughly the same up to 2x; for 3-4x batches, switch from a skillet to a sheet pan or stockpot so the food isn't crowded — overcrowding steams instead of browns.

Is Loaded Cheeseburger Casserole with Caramelized Onions low-carb?

Yes — this recipe is tagged low-carb based on its ingredient list. Always cross-check labels for packaged ingredients (sauces, broths, condiments) since formulations vary by brand.

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