You can make the crust from scratch, but it's easier to use a store-bought refrigerated pie crust, which is also delicious. Unroll it with the parchment paper it comes with and place it in a pie dish. Prick the bottom with a fork.

Cover the crust with parchment paper and fill with dried beans (like chickpeas) to weigh it down so it doesn't puff up. Bake in the center of the oven at 350°F (180°C), top and bottom heat, for 12 to 13 minutes. Meanwhile, finely dice the leek and cut the jamón into strips. If you have a slice of sandwich cheese left over, you can use it too.

Sauté the leek over low heat until soft. Remove from heat and set aside. In a bowl, beat the eggs and mix with the heavy cream and milk until well combined.

Add the leek, jamón, sandwich cheese slice, and half of the Manchego cheese to the egg mixture. Mix well.

Remove the crust from the oven and let it cool slightly. Once cooled, pour in the filling and top with the remaining Manchego cheese. With the oven still on, place the quiche inside, increase the temperature to 400°F (200°C), and bake for about 30 minutes (time may vary by oven). Check doneness by inserting a knife—if it comes out clean, it's ready.

Grate some Grana Padano cheese. When there are 5 minutes left, open the oven and sprinkle it on top. Switch to broil and let the surface brown to your liking. Remove the quiche from the oven when done.

Let the quiche cool to room temperature, then transfer to a serving platter. I like to trim off any overbaked crust from the edges before serving.

You can now enjoy it! Reheat individual slices if you prefer it warm, or serve at room temperature—both ways are delicious.