Finely chop pork fillet and roast in a half of butter until golden. Add chopped champignons and onion. Fry all together about 3 minutes. Cover with vegetable broth, add allspice and bay leaf. Stew on low heat for about 20 minutes. Take the broth and meat out of the pot. Melt the remaining butter, add the flour, regulary stirring, gently roast, pour broth portions and cook until thickening. Place meat and champignons in the pot, pour with white wine, lemon juice, add salt, pepper and Worcestershire sauce. Decompose the mixture in heat-proof cocotte, sprinkle with grated cheese and bake in the oven at 180 degrees Celsius for about 10 minutes. Serve with slice of toast bread.