Heat oil in
large heavy saucepan or Dutch oven. Add roast and brown very well on all
sides over moderately high heat (this may take as long as 20 minutes).
Add onion, garlic and boiling water. Sprinkle meat generously with salt
and pepper. Cover and simmer until meat is very tender, about 3 hours.
Lift out meat. Drain all fat and liquid from the pan. Return meat to pan
and brown again until quite dark on the outside. Put meat on a hot
platter and keep hot.
Skim fat off
drippings form pan or chill drippings quickly by setting in ice water
and lift off fat. Return 3 tbsp (45ml) of this fat to the pan. Sprinkle
in flour and let bubble up. Measure liquid left from cooking after fat
was removed and add boiling water to make 2 cups (500ml) if necessary.
Remove pan from heat and add liquid all at once, stirring to blend well.
Return to moderate heat and cook until thick and smooth, stirring
constantly. Taste and season if necessary. Serve with toast.