Peel and core cippolline. Melt 2 tablespoons butter in sauté pan.
Sauté half of the cipolline onions for about 10 minutes and remove to sprayed large baking dish. Melt 2 tablespoons butter in pan and sauté remaining cipolline onions. Add these to the baking dish. Sprinkle the cipolline onions with sugar. Spoon currant jelly into center of each cipolline onion.
Melt remaining butter with sherry and pour over top. Cover with foil and bake at 350 degrees for 45 minutes. Remove foil, continue baking until tender and syrup begins to form. Serve immediately.