Gratin Of Turnips And Blue Cheese

• 4 anchovy fillets
• 120 ml whipping cream
• 120 gr crumbled roquefort
• 55 gr melted butter
• 1 gr nutmeg preferably (freshly ground)
• 1 gr pepper (freshly ground)
• 4 slices turnips
• 1 slice onion (yellow peeled)