Ingredients :

• Camembert — Choose a well-ripened one, not an industrial Camembert as hard as a brick. It should be soft under your fingers when you press on the box. A cheese that is too young won’t melt properly and will keep a slightly grainy texture. No need to remove the rind — it melts too and brings a stronger flavor.
• Potatoes — Waxy varieties: Charlotte or Amandine. they hold up during cooking, keep their slices well-formed, and don’t turn into mash when you handle them. Avoid floury varieties — they crumble and you’ll end up with a mush under the cheese.
• Onions — Two large classic yellow onions. Not red onions — they give a weird color once cooked. The key is to sauté them over very low heat for as long as needed until they are translucent and light caramel in color.
• Pastry — Puff or shortcrust, both work. Puff pastry gives a lighter, crispier edge. Shortcrust is denser and absorbs the egg-cream mixture better. A store-bought rolled pastry works just fine.