Place each chicken breast half between 2 sheets of heavy-duty plastic wrap; pound to 1/4-inch thickness using a meat mallet or rolling pin. Sprinkle chicken with salt and pepper.
Heat oil in a large nonstick skillet over medium-high heat. Add chicken; cook 2 to 3 minutes on each side or until golden brown. Remove chicken and keep warm.
Reduce heat to medium; add shallots and sauté 1 to 2 minutes or until tender. Add wine and scrape browned bits from pan; cook until wine almost evaporates. Add broth; bring to a boil over medium-high heat and cook 2 minutes or until reduced to about 2 tablespoons. Remove from heat; stir in stone-ground and Dijon mustards and next 3 ingredients. Spoon mustard cream over chicken.