Pre-heat the grill to high.
Place the cabbage in a pan with the sugar and white wine vinegar. Bring to the boil, reduce the heat and simmer for 12 minutes.
Place the toast on a baking sheet. Place the sliced tomatoes on top, sprinkle with cheese and drizzle with the Worcestershire sauce.
Place under the preheated grill for four minutes, or until the cheese has melted.
Serve the rarebit on a plate with some of the pickled cabbage to the side.