Preheat the oven to 180C (fan-forced).
Remove pastry from the fridge (you may need to leave it on the counter to soften if it has been in the fridge long enough).
Roll the pastry between two pieces of baking paper. You want it to be big enough to fill your quiche tin with a small overhang, but no larger.
Gently ease the pastry into the tin (Note 4), pressing the pastry into the corners and pushing down any overhang (this pastry does not shrink).
Prick the base of the pastry with a fork.
Spread the custard over the base of the pastry followed by the onion, tomato, goats cheese and regular cheese (or filling ingredients of your choice).
Place the quiche tin on a tray (this prevents any accidental spillage/leakage) and carefully pour on the egg mixture. If a lot of the filling is visible above the egg mixture you can push it down with a spoon.
Bake for one hour, and rest for at least ten minutes before cutting.