1 Wash and dry the large and small mushrooms. Separate the stalks from the caps of the large mush- rooms. Finely chop the stalks and the small mushrooms.
2 Squeeze the lemon. Put 2 table- spoons of the butter into a heavy-based saucepan, together with the lemon juice, and melt, stirring constantly. Add the large mushroom caps. Pour in just enough water to cover them. Season with salt and pepper and cook until the caps are just tender. Remove from the heat. Keep hot.
3 Peel and chop 2 of the shallots. Melt 2 tablespoons of the butter in a skillet. Add the shallots and finely chopped mushrooms and mix well. Add salt and pepper to taste and cook until all the liquid has evaporated. Remove from the heat. Keep hot.
4 Peel and chop the rest of the shallots. Melt 2 tablespoons of the butter in a small pan. Fry the shallots until they are golden- brown. Add half the shrimp and the paprika and cook, stirring, for 2 minutes. Sprinkle the brandy over the top and ignite it. When the flames die down, remove the pan from the heat. Keep hot.
5 Melt 2 tablespoons of the butter in a pan, draw off the heat and stir in the flour. Mix in half the milk, then add the rest. Return the pan to moderate heat and bring to boil, stirring all the time. Simmer for 1-2 minutes and add a pinch of salt and cayenne pepper. Keep hot.
6 Put the remaining butter and shrimp, 1 tablespoon of the cream and salt and pepper to taste in a blender. Blend until smooth. Add to the chopped, mushroom and shallot mixture and stir.
7 Add the shallot, shrimp and brandy mixture, the rest of the cream and the tomato catsup to the white sauce. Taste and adjust the seasoning.
8 Drain the 8 mushroom caps and place them, rounded sides down, on a heated serving plate. Fill them with the stuffing. Pour the sauce over the top and serve.