1tablespoonunsalted butter15g, cut into small chunks
Mix the flour, cheese, salt and butter in a food processor until fairly well mixed - it should be like breadcrumbs. Add the water one tablespoon at a time and pulse until it comes together in lumps.
Remove dough from the food processor, bring together in a ball and chill for 20min or more, if possible (although as long as not too hot, you can use straight away, it's just a little easier to work with chilled).
Preheat oven to 350F/175C and line baking sheet(s) with with parchment paper.
Roll out the dough to about as thin as you are comfortable rolling (about ⅛in/1mm) then cut out as you prefer either with small cutters or cut into small squares. Poke small holes into them, if you wish (it will help reduce bubbled up texture).
Put your shapes on to the prepared baking sheets and bake around 15min until starting to go golden.
If you would like to add flaxseed meal, add around 2-4 tablespoon to the flour-cheese mixture at the start.