For an extra layer of flavor, consider roasting the bell and banana peppers alongside the tomatoes and onions. Grilled cheese croutons make a delightful topping, adding a comforting crunch and cheesy richness. Adjust the amount of sugar to your preference, depending on the sweetness of your tomatoes. A swirl of crème fraîche or a drizzle of balsamic glaze can also elevate the presentation and taste. This bisque can be made ahead of time and reheated gently. Its flavors will deepen overnight.