Grind mustard seeds into powder
In a large bowl, mix soy sauce, sugar, and spices, plus water, then stir in drumsticks to coat. Dump everything into a baking dish
Let stand, covered, for 20 minutes, then bake chicken, still covered, for 30 minutes on preheated 350 F
When 30 minutes is up, take off the aluminum foil cover, and continue baking for 1 H
Flip chicken, then broil for 8-10 minutes, if you like