Place the roast, potatoes, hot water, carrots, tomato soup, onion, celery, Worcestershire sauce, browning sauce (if desired), bouillon granules, garlic, sugar, salt and pepper in a 5–6-quart slow cooker. Cover and cook on low for 6–8 hours or until meat is tender.
Combine cornstarch and cold water in a small bowl until smooth; gradually stir into stew. Stir in peas. Cover and cook on high for 30 minutes or until thickened.