Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
Place the shredded mozzarella in a microwave-safe bowl. Microwave in 30-second intervals, stirring in between, until fully melted and smooth.
In a separate bowl, whisk together the almond flour, coconut flour, and Italian seasoning.
Pour the dry into the melted mozzarella.
Mix until combined, then season with salt and pepper to your taste.
Add the whisked egg and mix it in. Use your hands to knead the mixture until a smooth, uniform dough ball forms.
Place the dough ball on your parchment-lined baking sheet.
Press the dough out into a large rectangle using your hands or a rolling pin. If it's sticky, place another sheet of parchment on top to roll it out.
Layer the ham, pepperoni, and cheddar cheese slices evenly across the surface of the dough, leaving a small border around the edges.
Starting from one of the long sides, carefully roll the dough up into a tight log, enclosing the fillings.
Place the stromboli seam-side down on the baking sheet and brush the top and sides with the melted butter.
Bake for 17-20 minutes, or until the crust is golden brown and firm to the touch.
Let the stromboli rest for at least 5 minutes before slicing and serving. This helps it hold its shape!
Don't overfill! Leaving a small border (about 1/2 inch) around the edges of the dough will help you get a good seal and prevent the fillings from spilling out.
