Onion Orange Chicken

This recipe was quite tasty, but it was not very filling. It is fairly easy to make

4 boneless chicken breast halves
4 tsp dijon mustard
1/2 med onion, diced
1 cup orange juice
2 tsp butter
2 tbl packed brown sugar

1. Preheat oven to 350F
2. Place chicken in a baking dish and spread mustard evenly over each piece. Sprinkle onion over chicken, pour juice over all, place 1/2 tsp butter next to each piece of chicken. Bake uncovered for 25 min.
3.Flip chicken and sprinkle brown sugar over each piece. Cook until done 10-20 min