Meanwhile chop 2 rashers bacon and make rest into small rolls.
Fry chopped onion, tomatoes and bacon in most of the margarine, adding curry powder and Worcestershire sauce.
Grill or fry bacon rolls.
Take tops off potatoes, scoop out centre pulp, mash this with remaining margarine, season well and press or pipe back into potato cases, leaving a good-sized space in the middle.
Fill this with bacon mixture and top with a bacon roll.