Easy Creamy Bell Pepper Marinara

Ingredients (12)

• ✓ ¼ cup butter
• + 1 small onion, sliced add to pantry
• + ½ large red bell pepper, cut into matchstick-sized pieces add to pantry
• ✓ 1 clove garlic, minced
• + ¼ cup all-purpose flour add to pantry
• + 1 cup milk add to pantry
• + ½ cup grated Parmesan cheese add to pantry
• + 32 ounces tomato sauce (such as Classico® Tomato and Basil Sauce) add to pantry
• + ¼ teaspoon ground black pepper add to pantry
• ✓ ½ teaspoon balsamic vinegar
• + 1 dash hot sauce, or to taste add to pantry
• + 1 ½ cups chopped fresh spinach add to pantry