Add almond flour, coconut flour, xanthan gum, baking powder, and salt to a bowl. Whisk until combined. Add the vinegar and whisk again.
Crack the eggs into another bowl and whisk. Add it to the bowl with the dry ingredients and mix until a dough forms. Add the water and mix using a wooden spoon as needed. The dough should be firm yet slightly sticky.
Wrap the dough in cling film and knead through the plastic for a couple of minutes. Transfer to the fridge and rest for 10 minutes. Meanwhile, prepare the garlic herb filling.
Add the room-temperature butter to a bowl. Mince the garlic and finely chop the parsley. Add them to the bowl along with the dried oregano, dill, and parmesan cheese. Mix to combine, and set aside.
Preheat your oven to 350F/180C. Take the dough out of the fridge and divide it into two pieces. Roll each one between 2 pieces of parchment paper into a rough rectangle.
Spread the garlic herb mixture onto one of the rolled-out dough sheets. Place the plain dough sheet on top. Trim the edges into a large triangle.
Cut horizontal strips into the dough, keeping the center of the triangle intact. Twist gently, pinching the dough together to seal it closed. It should look like a Christmas tree at this point.
Make a star and a tree base out of the trimmings and attach them. Brush with egg wash and bake for 18-20 minutes until the tree begins to brown. Don’t overbake it; it needs to stay soft and moist.
Take it out of the oven and optionally garnish it with fresh herbs and crushed red pepper. Serve immediately!