In a large frying pan, heat lard and place chicken in pan. Fry until golden. Add marinade and enough chicken broth or water to cover. Reduce heat and simmer until tender. When done, remove to a serving platter and keep warm.
Strain the cooking liquid and reduce slightly. Beat egg yolks and cream in a bowl and slowly add some of the cooking liquid. Stir constantly to obtain a smooth sauce. Add mushrooms. Pour sauce over chicken and serve hot.