Line a 1 kg (2 lb) loaf tin with greased greaseproof paper.

Melt the margarine, stir in the flour. Add the milk and bring to the boil, stirring. Cool slightly, then beat in the eggs. Season and cool.

Cook the carrots and onion in the oil for 5 minutes. Blend in a liquidiser with a quarter of the sauce, pour into the tin.

Repeat with 225 g (8 oz) of the Cheddar. watercress and another quarter of sauce. Blend the cauliflower with the remaining Cheddar and a third quarter of the sauce.

Finally blend the peas and remaining sauce in a liquidiser. Pour into the tin.

Cover the tin with foil and stand in a roasting tin half-full of hot water. Cook in a moderate oven for 1 1/2 hours. Leave to cool. Refrigerate for 1 - 2 hours before turning out to serve. Garnish as above.