Salty cured ham, gooey cheese, caramelized onions and a creamy mustard sauce is all you need to make this incredible easy and delectable Ham and Cheese Puff Pastry. Plus, it's so easy to make you can almost do it in your sleep!
Thaw the puff pastry according to the instructions on the box. Preheat the oven to 400 degrees.
Cook the diced ham in a skillet for 3-5 minutes, until it is slightly caramelized.
Lay each sheet of puff pastry flat on a parchment paper lined baking sheet.
Combine all the ingredients for the mustard and mix well. Spread the sauce over the puff pastry sheets (there should be enough for 2 tarts).
Spread the cheese, ham, and caramelized onions on top. Bake for 20-25 minutes, until pastry is golden brown.
Slice and serve alone or with a fried egg on top for brunch/breakfast.
Place the thinly sliced onions and butter in a saucepan over medium heat. Cook, stirring periodically, until the onions are a golden brown and very soft. It should take about 15 minutes for the onions to get caramelized.
Substitute Gruyere or Emmental cheese for the Swiss cheese for an extra nutty flavor;
If you don't feel like caramelizing onions, you can use simple sauteed onions as well. I don't recommend raw onions as they will not cook fully during the baking process;