Ground Beef Spinach Casserole

Get ready for the ultimate comfort food mashup that’s about to become your weeknight hero!

This Ground Beef Spinach Casserole combines hearty ground beef with nutritious spinach in a creamy, cheesy embrace that’ll have everyone asking for seconds.

What makes this casserole absolutely irresistible is how all those flavors meld together – the savory beef mingles with earthy spinach while that melted mozzarella creates the perfect golden top.

Plus, it’s the kind of one-dish wonder that makes cleanup a breeze and leftovers even better the next day.

Ingredients

For the beef mixture:

• 1 pound ground beef
• 1 medium onion, chopped
• 1 clove garlic, minced (or more to taste)
• 1 (10 ounce) can sliced mushrooms, drained
• 1 teaspoon dried oregano
• 2 dashes hot pepper sauce (or more to taste)
• Salt and ground black pepper to taste

For the creamy base:

• 2 (10 ounce) packages frozen chopped spinach, thawed and drained
• 1 (10.5 ounce) can condensed cream of celery soup
• 1 cup sour cream
• 1 (8 ounce) package shredded mozzarella cheese

Steps

1. Preheat your oven to 350°F (175°C). This moderate temperature ensures even cooking without burning the cheese on top while allowing the flavors to meld perfectly throughout the casserole.
2. Heat a large skillet over medium-high heat until hot but not smoking. Add the ground beef, chopped onion, and minced garlic. Cook and stir continuously in the hot skillet until the beef is completely browned and crumbly, 5 to 7 minutes. The beef should have no pink remaining and the onions should be translucent. Drain and discard all the grease to prevent a greasy casserole.
3. Add the drained mushrooms, oregano, hot pepper sauce, salt, and pepper to the beef mixture. Simmer for 5 minutes, stirring occasionally. This step allows the seasonings to bloom and the mushrooms to release their moisture, concentrating the flavors.
4. Stir in the thawed and well-drained spinach, condensed cream of celery soup, and sour cream. Cook until the mixture is heated through and well combined, about 5 minutes. Make sure to squeeze excess water from the spinach beforehand – soggy spinach will make your casserole watery. Transfer the entire mixture to a greased casserole dish and spread evenly. Top with the shredded mozzarella cheese, covering the surface completely.
5. Bake in the preheated oven until the cheese is completely melted and beginning to turn golden brown around the edges, 15 to 20 minutes. The casserole should be bubbling around the sides when done. Let it rest for 5 minutes before serving to allow the filling to set up properly.

Smart Swaps

• Greek yogurt instead of sour cream (1:1 ratio) – adds protein without changing texture
• Cream of mushroom soup instead of celery soup for deeper umami flavor
• Fresh spinach (2 pounds) instead of frozen – sauté until wilted first
• Ground turkey or ground chicken for a leaner protein option

Make It Diabetes-Friendly

Replace the condensed cream of celery soup with 1 cup unsweetened almond milk mixed with 2 tablespoons cream cheese and 1 teaspoon garlic powder – this cuts approximately 8 grams of carbs per serving.

Use reduced-fat mozzarella to lower calories without sacrificing taste.

Serve with a side of roasted broccoli or cauliflower rice instead of traditional starches to keep the meal under 15 grams of carbs total.

The high protein content (about 25 grams per serving) helps stabilize blood sugar levels, making this an excellent choice for steady glucose management.

Pro Tips

• Squeeze spinach in a clean kitchen towel to remove every drop of water – this prevents a watery casserole
• Let the casserole rest 10 minutes after baking for easier slicing and serving
• Make ahead and refrigerate up to 2 days – just add 10 extra minutes to baking time
• Freeze individual portions for up to 3 months in freezer-safe containers