Absolutely! Go ahead and mix up everything you need now (as if you were about to pour it into a pie plate and bake it) and instead, keep it stored in a covered bowl or gallon-sized Ziploc baggie in the fridge. It can last up to two days like this but can be a great way to wake up to quiche on a busy morning. u003cbr/u003eDo not store the quiche filling in a glass pie plate and then move directly to a hot oven. If keeping in the pie plate until ready to bake, make sure to let it sit at room temperature for about 30 minutes as the oven preheats before baking.