Boil the potatoes in water until soft, and then drain.
Simmer the leeks or spring onions in the milk. Strain the milk into the potatoes and mash them, and then stir in the leeks.
Cook the cabbage in a little boiling salted water until just done, adding the rocket or watercress for the last minute or two. Drain and beat into the potato and leek mixture, with a little butter, if you like.
Melt the rest of the butter and add the lemon juice and a little pepper, and in it beat the prawns. Divide the colcannon between four plates, make a well in each heap, and spoon in the buttery prawns.
© 2000 Frances Bissell. All rights reserved.