Cook ground beef and onion in a skillet. Drain fat if needed and add worcestershire and seasoning. Scoop cooked beef mixture into crockpot and mix in cream of mushroom soup.
Stir in frozen carrots and frozen peas. Cover crockpot and cook on high 4 hours or low 8 hours.
Prepare instant mashed potatoes. Spoon mashed potatoes into frosting decorating tool with a large decorative tip. *or spread mashed potatoes with a spatula.