Ground Beef Cauliflower Casserole

The first time I made this casserole, my skeptical husband took three helpings and actually asked if there was pasta in it. That's when I knew cauliflower rice had done its job beautifully.

My sister came over for dinner last winter during a particularly rough week, and something about this bubbling dish just made everything feel better. We sat at the counter picking at the cheesy edges long after we should have stopped eating.

Ingredients

• 1 lb lean ground beef: The backbone of this dish, brown it well for those gorgeous crispy bits that add so much flavor
• 1 medium onion: Finely chopped so it virtually disappears into the casserole while adding sweetness
• 3 cloves garlic: Minced fresh because nothing compares to that aromatic punch
• 4 cups cauliflower rice: Fresh gives you better texture but frozen works perfectly fine in a pinch
• 1 medium red bell pepper: Diced small for little pockets of sweetness throughout every bite
• 1 cup baby spinach: Optional but I love how it wilts into almost invisible ribbons of green
• 1 cup sour cream: Full fat creates the most luxurious creamy base you can imagine
• 1 cup shredded cheddar cheese: Sharp adds the best contrast to the mild beef and cauliflower
• 1/2 cup shredded mozzarella cheese: For that classic bubbly golden top that makes everyone reach for seconds
• 2 tbsp olive oil: Helps sauté the vegetables to perfect tenderness
• 1 tsp dried oregano: Earthy and comforting in all the right ways
• 1 tsp dried basil: Brightens up the rich beef and cheese beautifully
• 1/2 tsp smoked paprika: This little pinch adds such incredible depth
• 1/2 tsp salt: Enhances all the flavors without overpowering
• 1/2 tsp black pepper: Freshly cracked makes a noticeable difference
• 1/4 tsp crushed red pepper flakes: Just a whisper of heat that lingers pleasantly
• 2 tbsp fresh parsley: Chopped and sprinkled on top for that final fresh pop

Instructions

Get your oven ready:

Preheat to 375°F so it's hot and waiting when you're ready to bake

Sauté the vegetables:

Heat olive oil in a large skillet over medium heat and cook onion and red bell pepper for 3-4 minutes until softened and fragrant

Add the garlic:

Throw in minced garlic and stir constantly for 1 minute until it becomes wonderfully aromatic

Brown the beef:

Add ground beef and break it apart with your spatula, cooking for 5-7 minutes until beautifully browned

Season everything:

Stir in oregano, basil, smoked paprika, salt, pepper, and red pepper flakes until the beef is coated in all those spices

Add the cauliflower:

Mix in cauliflower rice and spinach, cooking for 4-5 minutes until tender and any excess liquid has cooked off

Make it creamy:

Remove from heat and stir in sour cream and half the cheddar until everything is coated in that gorgeous sauce

Transfer to baking dish:

Spread the mixture evenly into a greased 9x13-inch baking dish, pressing it down lightly

Add the cheese topping:

Sprinkle remaining cheddar and all the mozzarella over the top in an even layer

Bake until bubbly:

Bake for 20 minutes until the cheese is melted, bubbly, and starting to turn golden brown in spots

Rest and serve:

Let it sit for 5 minutes to set, then scatter fresh parsley on top and serve while still hot and gooey

Save to Pinterest

This recipe has become my go-to for new parents and anyone who needs a meal they can just heat up and enjoy. Theres something about it that feels like a hug in food form.

Make Ahead Magic

Ive assembled this the night before and stored it in the refrigerator, then just baked it fresh the next evening. The flavors actually meld together even more beautifully that way.

Customization Ideas

Sometimes I add mushrooms or zucchini for extra vegetables, and ground turkey works wonderfully if you want something lighter. The base is so forgiving that almost anything works.

Serving Suggestions

A crisp green salad with a bright vinaigrette cuts through the richness perfectly

• Try serving it with steamed broccoli for extra low-carb vegetables
• A dollop of sour cream on top adds even more creaminess
• Leftovers reheat beautifully for lunch the next day

Save to Pinterest

Theres nothing quite like pulling this bubbling, golden dish out of the oven and watching everyone's eyes light up.

Recipe FAQs

→ Can I make this casserole ahead of time?

Yes, assemble the entire dish up to 24 hours in advance and refrigerate. Add 5-10 minutes to the baking time if baking cold from the refrigerator.

→ What other vegetables can I add?

Mushrooms, zucchini, diced carrots, or broccoli work well. Add them when sautéing the peppers to ensure they cook through properly.

→ Is this casserole freezer-friendly?

Absolutely. Wrap the cooled, baked casserole tightly and freeze for up to 3 months. Thaw overnight in the refrigerator before reheating at 350°F until warm.

→ Can I use frozen cauliflower rice?

Yes, frozen cauliflower rice works perfectly. No need to thaw first—just cook it slightly longer in step 6 to evaporate any excess moisture.

→ How can I make this dairy-free?

Use plant-based sour cream and shredded vegan cheese alternatives. Coconut yogurt can also work as a sour cream substitute in a pinch.