Preheat oven to 180°C/160°C fan-forced. Place 10g butter in a microwave-safe dish. Microwave on LOW (30%) for 20 to 30 seconds or until melted. Grease an 8 cup-capacity, 6cm-deep ovenproof dish with melted butter. Melt remaining butter in a saucepan over medium-high heat until foaming. Add flour. Cook, stirring with a wooden spoon, for 1 to 2 minutes or until mixture is bubbling. Remove from heat. Gradually stir in milk until smooth. Return to heat. Cook, stirring, for 2 minutes or until mixture has thickened and coats the back of spoon. Remove from heat. Stir in egg yolks, cheese and nutmeg. Season with salt and pepper. Using an electric mixer, beat egg whites until soft peaks form. Gently fold through cheese mixture. Spoon into prepared dish. Bake for 30 minutes or until golden and puffed. Serve with steamed vegetables.