In a bowl of a food processor combine the sharp, parmesan and gruyere cheeses. Add the onion, chili, and achiote powders, ground pepper, salt and flour. Pulse a couple of times to combine. Add the butter and pulse until the mixture is crumbly. Add the half and half until the dough just comes together.
Remove the dough from the food processor and transfer it to a very lightly floured surface. gather the dough into 2 rough squares or logs and wrap them in plastic wrap. Place the dough pieces in the freezer for about 30 minutes.
Preheat your oven to 350 degree Fahrenheit and line 2 baking sheets with parchment paper.
Remove one piece of dough from the freezer and unwrap. Lightly sprinkle your counter with flour and place the ball of cheesy dough on top. Roll the dough into a rectangle that is about 1/8" thick. You can go as thing as 1/16, but I don't know how to measure that thin. Just get it as thin as you can. Keep lifting the dough to ensure its not sticking to the surface. Lightly sprinkle with flour as needed.
Cut the dough into 1-inch squares either using a square cutter or eye-balling that sucka. Poke a hole in the center of each square using the flat end of a bamboo skewer or a small pastry tip.
Carefully transfer the squares to a your prepared baking sheet and lightly sprinkle with kosher salt.
Bake the squares for 12-15 minutes or until the end begin to brown, rotating the pan halfway through. Remove from the oven and allow them to cool for about 5 minutes or so. They harden as they cool, so try not to over-bake them unless you like real crunchy crackers.
Repeat with the second piece of dough.
Makes a Discillion (made up number, more than a millon) crackers.