Sprinkle chicken with salt and pepper. Melt 2 tablespoons butter in large skillet, add oil. Add seasoned chicken and brown on both sides. Mash half of raspberries, press through a fine sieve to remove seeds. Refrigerate remaining berries.
In a small bowl, combine strained berries, wine, garlic, parsley and broth. Pour over chicken. Cover skillet, cook 15 minutes over medium heat. Complete now or make ahead.
MAKE AHEAD: Place the cooked chicken and sausage in separate containers with tight-fitting lids. Cool, refrigerate up to 24 hours. Reheat in a large skillet. Add butter as directed below. Garnish and serve as below.
COMPLETE NOW: Cook chicken in sauce until tender. Using a slotted spoon, place hot chicken on platter. Keep hot. Stir green peppercorns into sauce; remove from heat. Add 1/4 cup butter, 1 or 2 pieces at a time, stirring constantly, until butter is blended into sauce. Immediately spoon over hot chicken, garnish with reserved raspberries and enoki mushrooms, if desired. Serve hot.
