When spring and summer bring warm days, I keep our meals light and garden-fresh with a minimum of cooking. Cold soups, abundant salads, tapas, and antipasti are elevated to dinner course level, providing simple and refreshing nourishment, while greedily taking advantage of the farmers market bounty. The trick to eating this fresh is to provide enough substance to call these dishes a main course—and for this, I often turn to shrimp. Shrimp are versatile and packed with protein, iron, and omega-3 fatty acids, adding the necessary nutritional oomph to top off a light meal. They require mere minutes to cook in a pan or on the grill, which is ideal for busy schedules and keeping the heat out of the kitchen. They can also be poached ahead of time and served chilled, such as in this gazpacho soup. Gazpacho is a cold tomato soup of Spanish origin that is traditionally …