1. Heat 1 tbsp butter, saute onions and garlic for 1 mt.
2. Add potatoes and saute till a little brown (be careful not to break them).

To make white sauce:

1. Heat 1 tbsp butter add 1 tbsp cornflour cook for 1 mt add 2 cups milk and cook till a little thick.
2. Preheat convection oven at 180 C.
3. Grease ovenproof dish.
4. Pour a little white sauce on the base.
5. Layer with onion-potato mixture.
6. Pour white sauce. Grate cheese.
7. Garnish with mixed herbs and bake for 20 minutes.