Cut the meat, mushrooms and onions into small pieces and fry in vegetable oil to evaporate all the liquid, then pour in the cream, add the flour and mix well. Season to taste and cook until the cream is thick.
Arrange the julienne on tartlets and sprinkle with grated cheese. Bake in a preheated oven to 180 degrees for 15-20 minutes.
Julienne in tartlets is ready, can be served warm and cold.