Chicken with Escarole and Warm Mustard Dressing

In a large bowl combine escarole and fennel; set aside. Season chicken with salt and black pepper. In an extra-large skillet heat 2 Tbsp. of the olive oil over medium-high heat. Add half the chicken to skillet; cook 4 minutes or until browned and no longer pink, turning once. Transfer to a plate; cover with foil to keep warm. Repeat with remaining chicken.

For dressing: Add shallot to skillet. Cook and stir 30 seconds. Add vinegar; stir until evaporated, scraping up any browned bits. Pour 1/2 cup water into skillet; cook, uncovered, 2 minutes or until reduced by about half. Remove from heat. Whisk in mustard and remaining 2 Tbsp. olive oil. Pour 3 Tbsp. dressing over escarole and fennel, tossing lightly. Season with salt and black pepper.

Stir any accumulated juices from chicken into dressing in skillet. Serve with chicken and escarole mixture.