Preheat oven to 200 degrees celsius fan-forced (390 degrees fahrenheit).
Lightly grease a 12cm x 36cm (5 x 14 inch) loose-bottomed pie or tart tin.
Place one sheet of the puff pastry into the tin and press down. Use the second piece to cover any gaps that remain.
Place the cheese (chopped unto chunks) into the Thermomix bowl. Grate for 8 seconds, Speed 8. Set aside. Wash and dry the Thermomix bowl.
Place the bacon and onion into the Thermomix bowl. Chop by pressing Turbo 3-4 times (or until chopped to your liking).
Add the olive oil and saute for 4 minutes, 80 degrees, Speed 2 (Reverse). Drain off any excess oil and then place the bacon and onion into the tin on top of the pastry.
Sprinkle over half of the cheese.
In the Thermomix bowl (no need to clean it this time), add the eggs and crream or milk and mix for 10 seconds, Speed 6. Pour the egg mixture into the tin.
Sprinkle over the remaining cheese.
Bake in the oven for 20 minutes or until golden and cooked through. Allow to stand for 10 minutes before serving.