4 (6 ounces each) boneless, skinless chicken breasts
1/4 Teaspoon salt
1/4 Teaspoon pepper
2 Tablespoons olive oil
1/4 Cup dry white wine, or chicken broth
1/2 Cup heavy cream
2 Tablespoons Dijon mustard
1 Teaspoon dried tarragon, (or 1 tablespoon chopped fresh)
Sprinkle chicken breasts with salt and pepper. In a large skillet, heat oil over medium-high heat. Add chicken; saute until cooked through, 10 to 12 minutes, turning once. Transfer to a plate; keep warm.
Pour wine into hot skillet; cook, stirring, until reduced by half, about 1 minute. Whisk in cream, mustard, and tarragon. Cook, whisking, until thickened, about 2 minutes.
Pour any accumulated chicken juices into sauce. Right before serving, drizzle cream sauce over chicken.