1 1/2 cups dried Italian butter beans or gigante beans (10 ounces), soaked overnight and drained
1 bay leaf
Salt
1/2 cup finely chopped red onion
1 tablespoon Champagne vinegar
2 teaspoons finely grated Meyer lemon zest (or 1 teaspoon lemon zest)
3 tablespoons Meyer lemon juice or 2 tablespoons lemon juice
1/4 cup plus 2 tablespoons extra-virgin olive oil
Freshly ground pepper
2 tablespoons chopped flat-leaf parsley
1 tablespoon chopped tarragon