Spray an eight-quart pot with cooking spray.

Add onions and garlic. Add roast and brown, over high heat, on all sides. Add salt and pepper.

Lower heat and cook covered four hours. Do not add water; the meat and onions will give off liquid.

Cool and slice the meat. (This can be done the day before.)

Return the meat, onions, and garlic to the pot. Add bay leaves, white wine, more seasoning if necessary, and chestnuts. Bring to a boil. Lower heat and cook for one hour.

Cool and refrigerate or freeze (freeze gravy separately) until using.