Sautéed bell peppers can be made a day before you need to use them and then stored in an airtight container in the fridge. You can then serve them cold or quickly reheat them in a pan or in the oven. You can also cut the peppers two or three days ahead of time and keep them covered in the fridge until you are ready to cook them. That is, if they make it that long- we love snacking on sliced bell peppers in our house!