Preheat the oven to 100 °. Wash the medallions, pat dry and fry in hot lard on both sides. Salt and let rest on a preheated plate in the oven for about 5 minutes.
Put the stock, sherry and green pepper in a pan and heat. Stir in the crème fraiche and let it boil down very slightly (caution: do not simmer too long, otherwise the sauce will thicken very quickly!). Season again to taste and pour over the meat, serve.
It goes well with ribbon noodles and a broccoli / cauliflower vegetable or lettuce.