Meyer Lemon-Honey Mustard:
1/4 cup Dijon mustard
1 heaping tablespoon clover honey
1 tablespoon fresh orange juice
1/2 teaspoon lemon zest
1 teaspoon fresh Meyer lemon juice, from Meyer lemons, if possible
Salt and freshly ground black pepper

Burgers:
1 1/2 pounds 90-percent lean, freshly ground turkey (not all white meat), chilled
Salt and freshly ground black pepper
8 slices goat cheese, sliced 1/2-inch thick
4 sesame seed hamburger buns, split and lightly grilled
Watercress, for serving