Lately, it's been too hot to turn on the oven or tend anything cooking on the stove. In our house, salads rule. However, not every salad begins with lettuce. This lentil and chicken salad, bumped up with chunks of crisp cucumber, sweet raisins and salty feta cheese, defines the kind of meal-in-a-bowl dishes we love, and because there's no mayonnaise, it's perfect for picnics or potluck. If your market sells pre-cooked lentils (in airtight packages, in the produce section of the store), and rotisserie chicken, this salad becomes a very easy assembly job. If you're cooking lentils and grilling a chicken breast, it's still a quick and easy summer lunch or supper. You can make the salad several hours ahead, and store in the refrigerator until it's time to serve.