Preheat the oven to 450 degrees F.
With a sharp knife score the fat of the ham in a diamond pattern. Rub generously with salt and pepper. Mix together the mustard and brown sugar and spread all over the ham.
Set the ham on a rack in a roasting pan, fat-side up, add 1 cup of the beer and 1 cup of the apple cider, the cloves and the bay leaves, and roast for 20 minutes.
Reduce the oven temperature to 325 degrees F. degrees and continue roasting, basting occasionally with the pan juices, until a meat thermometer inserted diagonally into the thickest part of the ham registers 155 degrees F. about 3 1/2 to 4 hours. As the ham roasts, replenish the beer and the cider in the pan. If the top of the ham brown too much, cover it loosely with foil.
Remove the ham from the oven and let stand, covered loosely with foil, for about 30 to 40 minutes, during which time the internal temperature will rise. Carve the ham into thin slices and serve with the pears.
Recipe courtesy Anya von Bremzen, Please to the Table: The Russian Cookbook, Workman Publishing, 1990