Yes! This is the magic of veggie quiches. The best way is to freeze the crust and filling separately. Prep all of the filling (veggies + milk and egg mixture) and then put it into a bag or freezer safe container and freeze for up to 3 months. To use it, let the filling defrost in the fridge overnight or place the container of filling into a pan of water to defrost faster. Then pour the filling into the pie crust and bake as you would normally. I double or triple the filling often and keep a few bags in the freezer alongside frozen store bought crusts for easy quiche making in the future. Quiche leftovers can be frozen as individual servings as well in tightly sealing containers for 1-2 months. Defrost in the refrigerator overnight or on the defrost setting on your microwave. The crust will not be crisp but it will still be tasty!