Step 1

In large skillet over medium-high heat, melt 2 tablespoons butter. Add chicken breasts in single layer. Cook just until no longer pink in middle, about 2 minutes per side. Set aside.

Step 2

Wipe skillet clean, and return to medium-high heat. Add 2 tablespoons butter, then add shallots and cook 1 minute. Add mushrooms, pepper and salt, to taste. Cook 4 minutes, or until mushrooms are golden brown. Add flour and stir for 30 seconds.

Step 3

Pour in ⅔ cup Marsala and chicken broth, and bring to boil. Stir to scrape brown bits from bottom of pan. Cook until very thick, about 3 minutes. Add chicken and cook until just heated through. Stir in remaining Marsala, followed by remaining 2 tablespoons butter. Continue to stir until butter melts. Season with salt, to taste.

Step 4

Divide among 4 plates. Garnish each with thyme leaves.

Step 5

Serves 4.