To roast peppers in oil, char them before cooking, use olive oil to coat the peppers and use a variety of seasonings, suggests Food Network. To char the peppers, put the uncut peppers on the burner of a gas stove or on a grill and char each side.
After removing the peppers from the charring process, coat them in olive oil and either place them in a bowl to steam over the flame for 15 minutes or until soft. Alternatively, place them on a baking sheet and bake at 400 degrees Fahrenheit for about an hour. Coat with more oil, garlic, vinegar and oregano. Add salt and pepper to taste.