Recipe from Bon Appétit, April 2011
Serves 4

Ingredients:

4 skinless boneless chicken breast halves
Coarse kosher salt
2 1/2 Tbs. butter, divided
2 Tbs. olive oil, divided
2 Tbs. shallot, minced
1/4 cup dry white wine
1 cup low-salt chicken broth
2 tsps. Dijon mustard
2 tsps. fresh tarragon, chopped 
2 bunches radishes (such as red, pink, purple, and white; about 20), trimmed of all but 1/2 inch of green tops, halved lengthwise
Fresh tarragon sprigs (for garnish)

Directions:

Sprinkle the chicken with salt and pepper. Melt 1 tablespoon of butter with 1 tablespoon of oil in a large skillet over medium-high heat. Add the chicken to the skillet and cook until browned and cooked through, 5 to 6 minutes per side, depending on thickness. Transfer the chicken to a plate and cover to keep warm. Add the shallot to the same skillet and stir over medium-high heat, about 1 minute. Add the wine, then the broth to the skillet and bring to a boil. Whisk in the mustard and chopped tarragon and boil until the sauce thickens enough to coat a spoon lightly and is reduced to 1/2 cup, about 5 to 6 minutes. Stir in 1/2 tablespoon of butter and set aside.

Meanwhile, melt the remaining 1 tablespoon of butter with the remaining 1 tablespoon of oil in heavy medium skillet over medium-high heat. Add the radishes and sprinkle with the coarse salt and pepper. Cook without stirring until the radishes begin to brown, about 4 minutes. Continue to cook radishes until crisp-tender, stirring occasionally, about 5 to 7 minutes longer.

Cut the chicken breast halves crosswise into 1/2″ thick slices; arrange on a platter. Place the radishes around and over the chicken. Spoon the sauce over the chicken and radishes. Garnish with tarragon sprigs and serve.