Preheat the oven to moderately hot
190C (375F/Gas 5). Grease a 2 liter soufflé dish, then dust with the
breadcrumbs. Cook the broccoli in boiling water, partially covered,
for 3 minutes, then drain and pat dry. Chop the broccoli roughly.
Melt the butter in a large pan. Stir in the flour and cook for 1
minute. Remove from the heat and gradually add the milk. Return to
the heat and stir until the mixture thickens. Cook over low heat,
stirring, for 1 minute. Remove from the heat and stir in the Cheddar
and 3 tbsp of the Parmesan. Separate the eggs and beat in the egg
yolks, one at a time. Season with salt, pepper and nutmeg. Cool
slightly, and fold in the broccoli.
Beat the egg whites to soft peaks, then stir
a third into the sauce. Very gently fold in the remaining egg white with a
metal spoon. Pour into the dish and sprinkle with the remaining Parmesan.
Bake the soufflé for 30-35 minutes, or until it is well risen and golden.
The centre should be creamy and soft. Serve immediately.