First rinse the liver, pat dry and remove the skin. Then fry with a little butter and the garlic over medium heat for about 5 minutes (the liver should still be pink in the middle). Puree the liver with marsala and sage in the food processor. Using 150 g butter, loosen the meat stock from the pan and add to the paste. Season the whole thing well with salt and pepper and divide it into 4 molds. Melt the remaining butter in a clean saucepan and place on the surface of the pate. Garnish with the sage leaves and chill.