Melt the cheese in the milk add the flour, bread crumbs and mustard and cook on a low heat for 1-2 minutes.
Blend in the egg and worchester sauce in a small blender. Roll out between two sheets of greaseproof paper to about 5mm thick and allow the mix to set in the fridge.
Slice each tomato into 6 slices and spread out on a large baking tray sprinkle with sugar, salt, pepper, thyme leaves, balsamic and olive oil and place in the oven on its lowest setting for 20 minutes.
Grill the haddock when half turn it over and place a piece of rarebit on top and grill until golden brown. Arrange the tomatoes in a circle on the plate, top with the haddock and some lightly dressed rocket leave.