Store leftovers in an airtight container in the refrigerator for up to 2-3 days. To reheat, place the stuffed mushrooms on a baking sheet and warm in a preheated oven at 350°F (175°C) for about 10-15 minutes. Avoid microwaving to retain texture. Variations include using ricotta instead of cream cheese for a cheesy option, adding jalapeños for spice, or making a vegetarian version with broccoli and cheese.