This recipe goes with the Grilled Tuna Sandwich with Red Peppers recipe.
Grill bell pepper until skin begins to blister and pepper begins to turn limp. Add tomato to grill a minute or two after starting the pepper. Grill the tomato until it just begins to turn limp. Remove from grill and let cool. Coarsely chop pepper and tomatoes; combine with remaining ingredients. Let sit uncovered at room temperature while fish is cooking.