Preheat the oven to 200°C (approximately 400°F). Rinse the broccoli, blanch in boiling salt water for 5 minutes, drain, rinse in cold water, and drain.
Melt the butter and sprinkle with flour. Deglaze with 500 ml (approximately 2 cups) of the broccoli cooking water. Whisk so that there are no lumps. Stir in the cream and cheese. Season with salt, pepper and nutmeg. Simmer over low heat for 3 minutes.
Divide the broccoli between 4 buttered, ovenproof ramekins. Pour the sauce over the broccoli. Mix the breadcrumbs and butter. Pour over the ramekins. Bake for 20 minutes, until golden brown. Remove from the oven and serve immediately.