Peel and wash the carrot. Cut it into brunoise. Peel and slice the onion. Clean the ceps. Cut them into slices.
In a casserole, melt 20 g of butter, sweat the onion, add the lentils and the carrot. Moisten with the white poultry stock. Cook for 25 minutes at low temperature (or 17 minutes in a pressure cooker).
Brown the ceps for 5 minutes in 20 g of butter over high heat, add the cream. Make a reservation.
Pan fry grenadins to desired doneness.
Serve immediately, accompanied by lentils and creamed porcini mushrooms.