Crumbly and toasty, these oat biscuits are the perfect accompaniment for a Christmas cheeseboard. They go great with all cheeses, but especially cheddars and stilton.
Sieve the flour, cream of tartar and bicarbonate of soda into a bowl. Add the sugar and oats. Add the butter, using your fingertips to rub the butter into the flour mixture to form a sandy texture. Add four of the egg yolks and work the mixture with your fingertips to form a dough.
Divide the dough into two equal pieces. Use your hands to roll each piece of dou