Preparation
Peel, wash, and dice the celery and potatoes. Cook in salted water for 25 minutes.
Shallot peel and half. Chop chocolate. Dice the butter and cool. Wash lamb fillets, dab dry, free from tendons if necessary. Drain the vegetables and beat with the remaining butter. Keep the mash warm.
Fillets salt and pepper. Serve with the shallots in the hot oil for about 6 minutes. Remove the fillet and shallots from the pan. Brush the fry with wine and allow to simmer for 1 min. Add the broth and chocolate and heat until the chocolate melts. Gradually add the butter cubes until the sauce easily binds (do not boil). Season the sauce and serve with fillets, shallots and puree.