1 1/2 lbs. rare roast beef, cut into 1/2" strips
1 lb. fresh mushrooms, sliced
3 shallots or 1 sm. red onion, finely chopped
3 tbsp. butter
1/2 c. port or Marsala wine
1/2 tsp. Dijon mustard
Salt & fresh ground pepper to taste
1 (10 oz.) pkg. Pepperidge Farm frozen puff pastry shells, baked according to directions

Heat 1 tablespoon butter in skillet, add shallots and mushrooms and saute until golden brown. Add beef, wine and increase heat, stir until reduced to half. Add remaining butter and stir quickly into mixture. Serve immediately in warm pastry shells.

Serves 6. (Excellent quick way to use leftover roast.)