Lightly grease two baking trays.
Sift together the flour and salt, then stir in the ground almonds.
Rub in the butter or margarine until the mixture resembles fine breadcrumbs.
Stir in the cheese, then add the beaten egg and mix well to make a pliable dough.
Knead lightly, then wrap the dough in cling film and chill it for 30 minutes, or longer if you have time.
Roll the dough out on a lightly floured board to a thickness of 3mm/1/8 in.
Cut it into shapes, using a selection of small cocktail cutters.
Carefully transfer the shapes to the prepared baking trays.
Beat the egg yolk with the water and lightly brush the glaze over the biscuits, then sprinkle them thickly with seeds.
Bake the cheese nibbles in a moderate oven (180C, 350F, gas 4) for about 15 minutes, or until lightly browned.
Remove the hot biscuits from the trays and transfer them to a wire rack to cool completely.
Continue cooking batches of biscuits in this way until all the mixture is used, cleaning and re greasing the trays if necessary.