- 3 t salted butter, plus extra for greasing
- 3½ T flour
- 1 cup milk, heated
- ½ t salt
- ¼ t white pepper
- ¼ t mustard powder
- 100 g Parmesan, grated
- 100 g Gruyère, grated
- 5 free-range eggs, separated
1. Preheat the oven to 200°C. Brush a 20 cm round baking dish with melted butter.
2. Melt the butter in a medium saucepan, then add the flour. Cook until the flour is golden brown, then add the milk, whisking continually until the mixture has thickened. Add the salt, pepper, mustard powder and cheese and mix until combined. Allow to cool for 5 minutes.
3. Using an electric mixer, beat the egg whites until stiff peaks form, then whisk the egg yolks into the cheese mixture. Fold the egg yolk mixture into the egg white mixture, a third at a time.
4. Bake for 20 minutes until caramel in colour. Serve immediately.