I start by adding the flour, salt, and pepper to my food processor, then pulsing in the cold, cubed butter until the mixture looks like coarse crumbs. This step is quick, so I try not to overprocess it, since overworked dough turns tough instead of flaky. Keeping the butter cold at this stage is what gives the final crackers their light, crisp bite.
Next, I mix in the freshly grated cheddar, minced garlic, chives, rosemary, and thyme, pulsing just until everything is evenly distributed. I like to scrape down the sides of the bowl once so no dry pockets of flour get left behind. The dough should look crumbly but well combined at this point, with visible flecks of green herb throughout.
With the processor running, I drizzle in the ice water one tablespoon at a time until the dough starts clumping into a ball. I stop as soon as it holds together when pressed, since too much water makes the dough sticky and hard to roll. I then turn it out onto a floured surface and gently shape it into a flat disc.
I wrap the disc tightly in plastic wrap and refrigerate it for at least 30 minutes. This resting time firms the butter back up and relaxes the dough, which makes rolling so much easier. If I'm short on time, I pop it in the freezer for about 12 to 15 minutes instead.
Once chilled, I roll the dough out on a lightly floured surface until it's about 1/8-inch thick, aiming for as even a thickness as possible. Uneven dough bakes unevenly, so I take my time here. Using a pizza cutter, I slice the dough into small squares, then prick each one a couple of times with a fork.
I transfer the crackers onto a parchment-lined baking sheet, leaving a little space between each one, then sprinkle flaky sea salt on top. They bake at 375°F for 12 to 15 minutes, until the edges turn a deep golden brown. I let them cool completely on the tray so they crisp up fully before serving.