Place in the bowl of a stand-up mixer the flax seed, ground flax seed, flour, baking powder, salt, cold margarine.
With the paddle attachment, mix on low speed until the mixture resembles a coarse meal.
Stir in milk mixing just until a soft ball is formed. Do not over mix.
Divide dough into 3rds. ( Chill dough in plastic wrap for 10 mins if you feel it needs it. I have not had to do this unless its hot weather )
Lightly flour your work area and rolling pin. Roll out 1/3 of the dough to very thin. Cut into cracker size squares. ( a pizza cutter is great ). Transfer to ungreased cookie sheet and bake for about 20 minutes. Until golden brown for best flavor. transfer to cookie rack for cooling and repeat with the remaining dough.
Variations : I have not tried this but you can add 1 tablespoon powdered onion soup mix, Or 1 cup grated cheese, Or 1 tablespoon oregano with 1 cup mozzarella cheese.