Preheat the oven to 425 F and line a cast iron skillet with parchment paper.

In a food processor, combine the almond flour, xanthan gum, baking powder, sea salt, and rosemary. Pulse until combined.

Add in the diced, cold butter and shredded cheese. Pulse again until it starts to crumble and form into a ball. Finally, add in one egg and mix until the dough is one even mixture.

Place the dough into the cast iron skillet that's lined with parchment. Lightly fold the dough over itself in the pan so that it forms a ball (this helps prevent cracking during baking). Use your hands to evenly pat the dough out to about 1 inch thickness. The dough doesn't need to be exactly flush against the sides but close to the edge (the bread will expand slightly as it bakes).

Use your thumb to dimple the top and then brush the top lightly with the egg wash. Season generously with sea salt and rosemary.

Bake for 20-25 minutes in the oven. The bread should be nicely golden brown and sizzle a bit when removed. Allow it to rest until lightly warm to the tough before cutting into it (it's a very tender bread otherwise). Serve with smoked garlic confit if desired or some olive oil over the top.