Position a rack in the lower third of the oven. Preheat the oven to 425°F.

Remove the skin, up to but not including the shank, from the meat.

Score the fat and meat 1 to 1-1/2 inches deep in a diamond pattern 1 to 1-1/2 inches apart.

Mix together the salt, pepper and the other spices you selected.

Rub this mixture over the entire surface of the ham. Scatter the onion, carrots, celery and bay leag in a large roasting pan.

Place the fresh ham on the bed of cut vegetables. Roast for 30 minutes, then reduce the oven temperature to 325°F. Roast for 1 hour more. Mix together the wine and chicken stock, then pour over the meat.

Roast, basting every 20 to 30 minutes, until a meat thermometer inserted in the thickest part of the meat registers 185°F, 2-1/2 to 3-1/2 hours more, 4 to 5 hours or longer if the fresh ham is large (the temperature will continue to rise 5° to 10°F out of the oven). Remove the ham to a large platter, cover loosely with aluminum foil, and let stand for 30 to 60 minutes. Pour off the fat from the pan.

Bring to a simmer, scraping up the browned bits on the bottom of the pan. Strain the juices into a saucepan and boil until slightly thickened. Taste and adjust the seasonings. If you want to thicken the juices to make a gravy, mix together the water and cornstarch.

Whisk into the simmering, not boiling, juices. Bring to a boil, whisking to thicken. To carve the meat, cut it into slices starting at the shank end, keeping the knife perpendicular to the bone. Then make one long slice with your knife along the bone to separate the slices from the leg. Arrange the slices on a platter and serve with the pan juices or gravy, if desired.