Roasted peppers are an essential part of many diets, including several eastern european cuisines like serbian, croatian, and bulgarian. In these regions, cooks use sunflower oil instead of olive oil to preserve the peppers, as olives aren't indigenous to the area. Other cultures, such as hispanic, spanish, and italian, commonly char vegetables before using them as ingredients for sauces, stews, or as accompaniments for meats, cheeses, and bread. Most often the peppers are simply put on top of a stove burner until black on all sides, then peeled and seasoned and stored in olive oil. To prepare these peppers you can choose to roast them by baking, broiling, or grilling, all with excellent results. If you're going to use olive oil to preserve your peppers, choose one that's mild in flavor to let the peppers shine without the oil overpowering the mixture.