Ham and Cheese Croissants: homemade butter pastry is wrapped around tender ham and Swiss cheese and baked to brown, flaky perfection.
Roll out the dough into a rectangle that is roughly 9-inches by 25-inches. Use a pizza cutter, bench knife, or sharp paring knife to trim the sides neatly to an 8-inch by 24-inch rectangle. Working in a zig-zag pattern, cut the rectangle into 8 long triangles.
Gently separate the triangles to give you room to work. Lay two slices of ham across each triangle. Lay 1 1/2 slices of cheese over the ham, with the thinner half slice of cheese near the pointy tip of the triangle.
Working with one triangle at a time, gently grasp both of the corners of the base of the triangle. Gently pull to stretch slightly and begin to roll firmly but not tightly. You want it to hold together but not be squished together. Continue to roll, tugging gently back on the already rolled portion to slightly stretch the slack that hasn't been rolled yet. Do this until you reach the point of the triangle. There will be parts of the ham and cheese that stick out. This is okay.
Stretch to wrap the tip around and gently press it into place. Position this on a parchment lined pan with the tip resting on the pan. Do this with your remaining triangles, placing the rolled dough at least 3 inches apart on the pan to account for expansion in rising and baking. Whisk together a large egg with a pinch of salt until even in colour. Brush the tops lightly with the egg wash. Place in a warm, draft-free place to rise until the dough is puffy and slightly jiggly. Put the egg wash in the refrigerator to use again before baking.
Preheat the oven to 425F. Brush the tops of the croissant with the egg wash. Bake for 15 to 18 minutes, or until the pastry is puffed, set, flaky, and caramelized to a deep rosewood brown. Let the pastries rest on the pan for 5 minutes before transferring to a cooling rack. These are always best when eaten slightly warm on the day they were made, but if there is some weird circumstance in which they're not all eaten immediately, I have frozen them or refrigerated them and eaten them after reheating. They were wonderful.