Preheat the oven

• Preheat the oven to 190 °C (375 °F).

Make the dough

• Add the parmesan, white cheddar, kosher salt, oregano, red pepper flakes, flour, butter and sun-dried tomatoes to the bowl of a food processor.
• Pulse until the butter is broken down into lentil-sized pieces.
• Add the milk and pulse until incorporated; the dough should stick together when pressed between your fingers.

Knead the dough

• Turn the dough out onto a lightly floured work surface and knead briefly until you can form a solid block of dough.

Roll out the dough

• Lightly flour a work surface and roll out the dough on top of it until you get a roughly 50 x 40 cm rectangle.
• Roll it very thin, this is the key to getting crispy crackers.

Cut and dock the crackers

• Using a knife or fluted pastry cutter, cut the sheet of dough into small rectangles.
• Use a wooden skewer or toothpick to dock a hole into the center of each cracker, then sprinkle with kosher salt.

Bake the crackers

• Move the crackers to a parchment-lined baking tray and bake until the bottoms are golden brown.

Cool completely

• Move the crackers to a wire cooling rack and let them cool completely before enjoying.