Seafood Salad with Fennel and Green Beans

Name: Seafood Salad with Fennel and Green Beans
Ingredients: 1/2 lb green beans, stem ends trimmed; 1 (1 1/4-lb) live lobster; 3/4 lb cherry tomatoes (2 cups); 1/2 cup coarsely chopped red onion; 2 tablespoons red-wine vinegar; 3/4 teaspoon salt; 2 small fennel bulbs (sometimes called anise; about 1 1/2 lb total), stalks discarded; 2 tablespoons extra-virgin olive oil; 1 lb large shrimp in shell (21 to 25 per lb); 1 lb sea scallops, tough muscle from side of each discarded if attached; 1/4 teaspoon black pepper; 1/3 cup torn fresh basil leaves; Garnish: coarse sea salt; a green-bean frencher (optional); an adjustable-blade slicer