Wash the meat and dab dry. Peel the garlic and press it through the garlic press. Mix mustard, sherry and garlic. Turn the fillets in it and cover them and put them in a cool place for about 1 hour. In the meantime clean the leek and peel the carrots. Wash both and cut into thin strips.
Clean, wash and halve the mushrooms. Defrost the puff pastry. Dab chicken fillets dry, keep marinade. Fry chicken fillets in hot oil on both sides until golden brown. Add mushrooms and fry for about 5 minutes. Season with salt and pepper. Add cream, 200 ml water, marinade and remaining vegetables. Bring to the boil and season again. Cut the chicken fillets into slices and fill them into an ovenproof dish with the vegetables. Separate the egg. Brush the upper outer edge of the mould with egg white. Roll out 3 slices of puff pastry so that the pastry is approx. 3 cm above the dish all around.
Add cream, 200 ml water, marinade and remaining vegetables. Bring to the boil and season again. Cut the chicken fillets into slices and fill them into an ovenproof dish with the vegetables. Separate the egg. Brush the upper outer edge of the mould with egg white. Roll out 3 slices of puff pastry so that the pastry is approx. 3 cm above the dish all around. Cut out 1-2 holes. Place the dough over the tin and press the edges firmly together. Cut out stars from the remaining dough and decorate the top with them. Spread everything with whisked egg yolk. Bake in the preheated oven (electric: 200 °C/ gas: level 3) for 20-25 minutes. Serve garnished with chervil
Cut out 1-2 holes. Place the dough over the tin and press the edges firmly together. Cut out stars from the remaining dough and decorate the top with them. Spread everything with whisked egg yolk. Bake in the preheated oven (electric: 200 °C/ gas: level 3) for 20-25 minutes. Serve garnished with chervil