Morel and Crawfish Ragout Vol Au Vents

Rinse the celery, peel and thinly slice. Peel the carrot and finely chop. Trim the leek, cut in half, rinse and cut into thin rings. Cook the vegetables in 2 tablespoons hot oil for about 5 minutes. Add the Cognac and flambé. Add the wine and simmer until almost all liquid has evaporated. Add the sour cream and crème fraîche and simmer for 10-15 minutes. Season with salt and pepper. Rinse the morels under running water and dry on paper towels. Cut the larger mushrooms into pieces. Sauté the mushrooms in the remaining oil for about 10 minutes. Season with salt, pepper and a dash of lemon. Add the crayfish and cook until warmed through. To serve, fill the vol-au-vents with the mixture and drizzle with the sauce.