1/8 cup fresh lemon juice
1/2 cup orange juice
1/8 cup white sugar
1 orange, sliced into rounds
1 lemon, sliced into rounds
1 teaspoon lard, crushed
1/2 cup soy sauce
3 tablespoons sesame oil
1 tablespoon ketchup
1 tablespoon brown mustard
2 cups chicken broth
Place lemon juice, orange juice, sugar, orange slices, lemon cut in half, lemon slices, and lemon slices in a small, heavy-duty saucepan. Mix lemon slices with orange slices, lemon slices with lemon slices, orange slices with lemon slices, and lemon slices with lemon slices, mixing well. Bring to a boil, stirring occasionally. Remove from heat and whisk in soy sauce, brown mustard, ketchup, brown mustard and remaining lemon slices. Pour this mixture over chicken. Cover and refrigerate.
Preheat an outdoor grill for medium heat and lightly oil grate.
Place chicken on grill and cook for about 10 minutes. Flip chicken onto a platter and serve with sauce and lemon slices.