Spring Pea and Fava Bean Crostini

Name: Spring Pea and Fava Bean Crostini
Ingredients: 1 1/2 tablespoons unsalted butter, softened; 1 teaspoon minced chervil; 1 teaspoon minced tarragon; 1 teaspoon minced chives; 1/2 teaspoon finely grated lemon zest; 1/2 teaspoon fresh lemon juice; 1/4 teaspoon minced garlic; Salt and freshly ground pepper; 2 pounds fava beans in their pods, shelled (2 cups); 1 tablespoon extra-virgin olive oil; 1/4 pound thin asparagus, cut into 1/2-inch lengths; 1/4 pound sugar snap peas; 1/2 cup shelled fresh or frozen English peas (2 1/2 ounces); 2 shallots, thinly sliced; 3 tablespoons water; 4 slices country bread, toasted