Gruy-Arugula-utto-Stuffed Chicken Breasts with Caramelized Shallot Sauce

6 (4oz. each) skinless, boneless chicken breast halves
6 slices prosciutto
6 slices Gruyère cheese
1½ cups trimmed arugula
1/2 tsp. salt
3 tbsp. flour
1 tbsp. olive oil

1 cup thinly sliced shallots
2 tsp. tomato paste
2 cups dry white wine
2¼ cups chicken broth
1½ tsp. water
1 tsp. cornstarch

To prepare the chicken, place each chicken breast half between 2 sheets of
heavy-duty plastic wrap; pound using a meat mallet or rolling pin. Discard
plastic wrap. Top each chicken breast half with 1 slice each of
prosciutto and 1/4 cup arugula, leaving a ¼" border around edges. Fold in
half, pinching edges together to seal; sprinkle with salt . (The chicken
can be prepared up to a day ahead and refrigerated at this point.)

Dredge chicken in flour, shaking off excess. Heat oil in a large nonstick
skillet over medium-high heat. Add chicken; cook 5 minutes on each side.
Place chicken in a shallow baking pan; bake at 350° for 5 minutes or until
done. Keep warm.

To prepare sauce, add shallots to skillet; sauté 4 minutes over medium-high
heat or until browned. Add tomato paste; cook 1 minute, stirring
constantly. Stir in wine; bring to a boil over high heat. Cook until
reduced to 1 cup (about 6 minutes). Add broth; bring to a boil. Cook until
reduced by half (about 8 minutes).

Combine water and cornstarch in a small bowl, stirring with a fork until
smooth. Add cornstarch mixture to sauce; bring to a boil. Cook 1 minute,
stirring constantly.

6 servings