In a saute pan, over medium heat, melt 2 tablespoons of butter. Add the onions. Season with salt and pepper. Saute until wilted, about 2 minutes. Season both sides of the liver with salt and pepper. Season the flour with salt and pepper. Dredge
the liver in the flour, coating completely and shaking off the excess. In a large skillet, over medium heat, melt
remaining 2 tablespoons of the butter. When the butter
is hot, add the liver. Cook for 1 minute on each side, remove from the pan and set aside.
To serve, place a serving of the gratin
in the center of each plate. Lay a piece of the liver next to the gratin. Spoon the onions
over the liver. Garnish