Directions Core and slice the tomatoes, and arrange them in a serving dish. Sprinkle the shallots over the tomatoes. Whisk the olive oil and balsamic vinegar together with a fork, then pour over the tomatoes. Let stand for 5 minutes before serving, or refrigerate, covered, for up to 3 days. Eat with French bread, and dip the bread in the marinade when finished with the tomatoes.