Vegetarian Spinach and Mushroom Enchiladas

Ingredients (13)

• ✓ 3 tablespoons butter
• ✓ 1 pound mushrooms, cleaned and sliced
• + 1 cup coarsely chopped onion add to pantry
• + 8 ounces fresh spinach - washed, stemmed, and coarsely chopped add to pantry
• + salt and ground black pepper to taste add to pantry
• + salt and ground black pepper to taste add to pantry
• + 1 (10 ounce) can Mexican-style diced tomatoes with lime and cilantro (such as Rotel®), half drained add to pantry
• + 1 (8 ounce) package neufchatel cheese add to pantry
• + 1 (16 ounce) container sour cream, divided add to pantry
• + ½ teaspoon ground cumin add to pantry
• + 20 corn tortillas add to pantry
• ✓ 1 pound shredded Monterey Jack cheese
• + 1 (8 ounce) jar salsa, or as needed add to pantry