Champagne ham (champagneskinke)

15 pounds ham
10 cloves
1 teaspoon thyme
26 ounces champagne
1 cup sugar
2 medium onions, quartered
4 tablespoons flour

1. Place the ham in a roasting pan with water to cover. Bring to a boil on top of the stove over a high heat. Place the cloves in the ham, sprinkle the ham with thyme.
2. Roast 2 1/2 hours covered in a preheated 350 oven. Drain ham of stock, reserving 2 1/2 cups. Remove as much skin and fat as possible from the ahm. Pour the reserved stock back over the ham and add the bottle of champagne. Return to oven and let cook another hour, basting often.
3. Drain off the stock and reserve. Sprinkle ham with the sugar. Drop the onions in the pan.
4. Raise oven heat to 500 degrees, return ham to oven to brown and glaze. Remove ham to warm serving platter.
5. Mix flour with stock until smooth and cook over low flame, stirring constantly until it boils.
6. Carve ham and serve sauce individually over slices.