For convenience, you can reheat cooked stuffed peppers in the microwave for a couple of minutes or so. Place one or more on a microwave-safe plate and lightly cover with wax paper first. If you want to reheat several portions of stuffed peppers out of the refrigerator, you can bake them in the oven at 350 degrees F. Place them in a baking dish, cover with foil and bake for around 15 minutes. Remove the foil and bake for another five minutes.