Italian Chicken Meal Prep Casserole (Vegetarian option)

Name: Italian Chicken Meal Prep Casserole (Vegetarian option)
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Cuisine: Italian
Ingredients: 1 pound cooked chicken — shredded or diced (vegetarian sub in note); 1/3 cup sour cream or real mayo; 1 tablespoon Italian seasoning; Optional: 1/2 teaspoon garlic powder + 1/2 teaspoon onion powder (for extra flavor); 1 to 2 cups sliced or spiralized zucchini (pressed very well to remove excess water); 2 cups torn spinach; 1 1/2 cups diced cherry tomatoes (or equal amount canned Italian herb diced tomatoes, very well drained); Kosher salt and black pepper, to taste; Optional: shredded cheese or dairy-free cheese for topping