3 tablespoons butter
6 skinned and boned chicken breasts
1 (14 1/2-ounce) can chicken broth
1 medium-size sweet onion, diced
3 tablespoons all-purpose flour
3 tablespoons Dijon mustard
Melt butter in a large skillet over medium-high heat; add chicken, and cook 2 minutes on each side or until golden brown. Whisk together remaining ingredients, and pour over chicken. Cover, reduce heat to low, and simmer 20 minutes.