We're as guilty as anyone of lazy-salad syndrome. If we can get away with opening a box of prerinsed greens and throwing on a dab of supermarket dressing, we'll do it. For a side salad, that might be acceptable. But if we're making a salad as its own dish—for a quick summer meal, for example—it's inexcusably lame. With just a little effort, and really no time at all, we can prepare this white bean salad with ingredients we already have in the pantry. The only things we need fresh are cucumber, tomatoes, feta, and lettuce.
The centerpiece and main source of protein in the salad is cannellini beans. We use these white beans all the time in cool-weather dishes, such as pasta with broccoli rabe, since they have a great texture and hold their shape well, even when sautéed. Their creaminess also works in their favor when they're puréed for an appetizer dip. All these traits make them equally at home in this summer salad.
Now, there's no reason you couldn't use another variety of canned bean, of course, such as garbanzos or red kidney beans, but for our money, the texture of cannellini beans creates the best balance here. Don't forget to rinse and drain the beans well before you use them.
We're pairing the beans with briny olives and grape tomatoes, and adding some crunch with chopped cucumbers. The shallots (which you could also replace with some thinly sliced red onion) are mellowed by the marinade, so, while they contribute good flavor, they don't have too much of that raw oniony bite. Just like when you marinate a meat dish, the beans, too, will benefit from standing for a few minutes in the dressing. To brighten the flavor of the canned beans, we add a healthy dose of fresh lemon juice, well more than what's called for by the standard 3:1 ratio of oil to vinegar (or other acid) in a vinaigrette. Adding a little mustard helps to emulsify the dressing, along with providing a good savory kick.
Finally, the salad is finished with crumbled feta cheese. You can use whichever variety you prefer; we've found that a lot of brands available in supermarkets are either too bland (many domestic fetas are guilty of this) or way too salty, but if you can get an imported French or Greek version, you should be set.
While we've made this salad for at-home dinners, it would also travel very well for a picnic or potluck. But don't add the tomatoes and herbs until just before serving, since they would otherwise break down too much in the acidic dressing. We love using the tight leaves of a head lettuce, such as Boston (a.k.a. butter or Bibb), to form serving cups—which means that, if we were to take this salad out on the road, we wouldn't even need plates. See? I told you we were lazy.