If you’ve never made quiche with puff pastry, this recipe is a great place to start. It might sound fancy, but this step-by-step method keeps it simple.
Preheat the oven to 400F with the top rack placed in the middle of the oven. Grease a round glass pie plate.
Make the quiche:
On your counter, roll out the puff pastry until it's slightly larger than the top of the pie dish. Lift it and place it in the dish. Press it down, folding the sides over.
In a medium bowl, whisk the milk and 4 eggs. Add the salt, ham, half a cup of cheese, and chopped spinach. Mix well. Pour the egg mixture over the puff pastry, then sprinkle the remaining shredded cheese on top.
In a small dish, whisk the remaining egg. Use a brush to egg-wash the edges of the puff pastry to give them a nice golden color. I usually pour the remaining whisked egg into the quiche.
Bake for 25-35 minutes until the pastry is golden brown and the eggs are fully set. I set a timer for 22 minutes, and at this point, keep a close eye on the quiche. If I use a larger 9" pie plate, the cooking time is shorter; if I use a smaller 8" dish, the cooking time is longer. You're looking for a puffy middle (which means the eggs are cooked) and golden edges.
Remove it from the oven and let it cool for a couple of minutes before slicing.
Storage:
Refrigerate any leftover puff pastry quiche in an airtight container for up to 3 days. To reheat, use the microwave, the oven at 300F for 6 to 8 minutes, or the air fryer at 340F for 5 minutes.
Notes
Most puff pastry sheets are sold in packs of 2. I recommend only thawing out as many as you're going to bake.
Glass and ceramic pie plates bake hotter and are what I recommend to prevent an undercooked pastry dough. Metal, disposable pie molds do not retain the heat well and can be inconsistent (it can burn or be undercooked, depending on the type).
Fillings & Add-Ins: one sheet of puff pastry holds 4 eggs and ½ cup of milk, plus up to 2 ½ cups of add-ins, including the cheese. Most veggies (like mushrooms and onions) should be sautéed first, and the meat should be cooked.