Preheat the oven to 400 degrees F. Place the peppers in a parchment paper-lined baking pan. Roast, turning once or twice, until the peppers begin to char and blister, about 25 to 30 minutes. Set the peppers on a plate, cover with foil and cool to room temperature.
Peel the peppers; the skin should just slip off. Cut each pepper in half and remove the seeds. Slice the peppers into strips and place in a bowl; toss with the remaining ingredients.
Recipe Options: Spice up the relish by mixing in a pinch or two of crushed chili flakes. Use green olives in this recipe instead of black, or use a mix of both. Save yourself some time by slicing up the ready to use roasted peppers that are available in our deli department.