Bring several quarts of water to a boil in a large saucepan. Add the beans and salt to taste. Cook until crisp-tender, about 5 minutes. Drain, shake dry and then spread out over a clean towel so they dry quickly. Let the beans cool to room temperature.
Combine the tomatoes, shallot, oil, lemon juice, parsley and pepper to taste in a large serving bowl.
Add the beans and adjust the seasonings, using salt sparingly.
Sprinkle the feta cheese over the salad and serve immediately.
Variation: Use 1 tablespoon walnut oil and 1 tablespoon extra-virgin olive oil. Sprinkle the salad with 1/3 cup toasted and coarsely chopped walnuts and crumbed goat cheese (instead of the feta) just before serving.