Set your oven to 375°F (190°C). Lightly grease a 9×13-inch baking dish or line it with parchment paper.

Slice each croissant in half horizontally. On the bottom half of each croissant, layer a half-slice of cheddar, followed by a generous slice of ham, then another half-slice of cheese. Cap with the top half of the croissant to create a sandwich.

In a small bowl, mix the softened butter, yellow mustard, honey, and Worcestershire sauce until smooth and creamy. This spread is the secret weapon—it adds richness and flavor in every bite.

Gently open each sandwich and spread a small amount of the butter mixture on the inside before closing it again. This ensures every bite is infused with flavor.

Place all the sandwiches snugly in the prepared baking dish. In a separate small bowl, whisk the egg white with a splash of water to create an egg wash. Brush it over the tops of the croissants and sprinkle generously with poppy seeds.

Bake the croissants in the preheated oven for 15–18 minutes, or until the cheese is melted and the tops are golden brown. The glaze will give the tops a beautiful sheen and slightly crisp texture.

Let cool for a couple of minutes, then serve warm. These are best enjoyed fresh from the oven when the cheese is gooey and the croissants are perfectly crisp.