TOPPINGS ARE THE THIRD TIER of building the canapés. They add texture and color to the finished appetizer, not to mention great flavor. White Bean Salad: This Italian classic is made with creamy cannellini beans, and scattered with red bell peppers for color. Mushroom Sauté: Simple and plenty tasty, the earthiness of the mushrooms helps balance the assertive dips. Marinated Tomatoes: Another traditional topper — the key to this one is to use fresh basil and the ripest tomatoes. Sautéed Red Peppers: These peppers have an unexpected opposing tangy-sweet combination. The long simmer really intensifies their natural sweetness, because as the balsamic vinegar reduces, its flavor concentrates in the peppers. For the best flavor, serve all of the toppings at room temperature.