Preheat oven to 425° F.
Place roast, fat side up, in a roasting pan and rub fat thoroughly with salt.
Cut slits about 2 inches apart in the roast's fat and insert garlic.
Cook approximately 40 minutes to the pound, adding a little water from time to time to keep drippings from scorching.
When roast is done, remove from pan and keep warm.
Skim fat, then add 1/2 cup water to pan drippings.
Place roasting pan directly over a low flame and boil, scraping bottom of pan to loosen drippings.
Add 1 tablespoon Worcestershire sauce to pan drippings and stir.
Slowly add 1/4 cup cold water to 1 tablespoon flour and blend to make a thin paste.
Add to pan and cook, stirring constantly, until thickened.
Add more Worcestershire sauce to taste.