Heat 1 tsp Olive oil in a pan, and brown off the ½ Onion, diced and 3 rashers Bacon, diced then allow to cool.
Using a circle shaped cutter (that is slightly bigger than your mini muffin tray), cut out 24 circles of your 3 sheets Gluten-free puff pasty, frozen. You may need a small dusting of gluten-free flour here.
Lightly grease a mini muffin tray, and gently press your pastry circles into each hole.
Spoon in the onion and bacon mixture into each hole, as well as a sprinkle of the ½ cup Cheese, shreddedto each.
Combine the ⅓ cup Milk and 3 Eggs (and salt and pepper if using) in a small jug and whisk together. Gently pour the egg mixture into each pastry case, making sure not to overfill as the egg will rise as it cooks.
Bake in the oven for 12-14 minutes, or until the quiches are golden brown and appear 'set' on top. Rest for a few minutes, before transferring them to a cooling tray.