The classic recipes for roasted pepper use just red peppers, but you can use an assortment of colors—red, orange, and yellow. Keep a close eye on the yellow variety while they cook under the broiler to ensure that they don’t char; their flesh is delicate and you’ll lose the beautiful yellow color.
Preheat the Broiler. Cover a heavy baking sheet with foil. Arrange the bell peppers on the baking sheet and broil until the skins brown and blister, turning the peppers over occasionally, about 20 minutes. Enclose the peppers in a resealable plastic bag and set aside until cooled to room temperature.
Peel and seed the peppers, and cut them into strips. In a large bowl, toss the pepper strips with the oil, garlic, salt, and pepper. Cover and refrigerate for at least 5 hours, for the flavors to blend, and up to 1 day. Bring to room temperature before serving.