Cook shrimp in boiling salted water 2 minutes. Drain and cut into scallops. Place some clarified butter in a casserole dish on the heat. Add the onion, carrot and celery. Place the chicken on the bed of vegetables. Cover and allow to steam for 1 minute. In another pan on the heat place some clarified butter, add the mushrooms (vein side up), lemon juice, water and season with salt and pepper. Allow to cook gently 4 minutes. Cover the chicken with the stock and add the basil, parsley stalks and bay leaf. Bring to the boil and then allow the chicken to poach covered for 30 minutes. Melt the butter in the saucepan and then add the flour, forming a roux. Add the liquid from the mushrooms and then strain off 1 cup of the chicken stock and add to roux. Whisk until smooth. Season with salt and pepper. Bring to the boil and then simmer for 10 minutes, whisking from time to time. Add the egg yolk to the sauce and then the cream. Whisk to combine and then add shrimp and mushrooms to sauce with 1 tablespoon brandy. Remove chicken from pot. Slice off thighs at ball and socket joint and then remove the skin. Trim off first leg joint. Detach the whole breast at wishbone. Press down and then lift meat off the rib cage. Cut whole breast in half. Remove skin. Lay chicken on serving dish and coat with sauce. Decorate with slices of truffle.