Lilly's Sea Scallops with Mango and Jalapenos

Source: Chef Kathy Cary - Lilly's, Louisville, Kentucky

Serves 6 as an appetizer or 4 as an entree

Scallops
1 tablespoon Dijon mustard
1/2 teaspoon kosher salt
1/4 teaspoon pepper
2 tablespoons fresh tarragon
1 1/2 pounds sea scallops, cut in half horizontally
1/4 cup (1/2 stick) butter

Sauce
1/4 cup (1/2 stick) butter
3/4 cup chopped shallots
1 jalape