Ground Beef-Spinach Casserole

Ingredients (12)

• ✓ 1 pound ground beef
• + 1 medium onion, chopped add to pantry
• + 1 clove garlic, minced, or more to taste add to pantry
• + 1 (10 ounce) can sliced mushrooms, drained add to pantry
• + 1 teaspoon dried oregano add to pantry
• + 2 dashes hot pepper sauce, or more to taste add to pantry
• ✓ salt and ground black pepper to taste
• + salt and ground black pepper to taste add to pantry
• + 2 (10 ounce) packages frozen chopped spinach, thawed and drained add to pantry
• + 1 (10 ounce) can condensed cream of celery soup add to pantry
• + 1 cup sour cream add to pantry
• + 1 (8 ounce) package grated mozzarella cheese add to pantry