Sift or sieve flour, salt, baking powder and baking soda into a mixing bowl.
Add sugar, poppy seeds, lemon zest to the flour and mix well.
Cut the butter into tiny pieces. Or grate it over the flour mixture.
Using your finger tips only, rub the butter into the flour. The butter pieces should become smaller.
Don't over work this step as you may cause the butter to melt.
Make a well in the middle of the flour.
Add the whipping cream and milk.
Mix gently and bring the flour mixture together. Do not knead.
Dust the work top with some flour.
Tip the flour mixture onto the dusted with flour work top.
Using both your hands bring the dough together into a lump.
Pat the dough into a square about 6"X 6" and about 1" thick.
Dust a sharp knife with flour.
Cut the patted dough into four squares.
Stack the pieces on top of one another.
Pat the dough gently down again into a square about 6"X 6" and about 1" thick.
Stack the pieces on top of one another again.
Now pat the dough into a rectangle about 7½" X 5". It should be about 1" thick.
Cut the dough into half lengthwise using a knife dusted with flour.
Then cut each part into 3 squares. That way you will have 6 pieces.
Arrange the cut pieces on a parchment lined tray.
Sprinkle little sugar on top if you wish.
Put the tray in the freezer for 10-15 minutes.
After 5 minutes or so, preheat the oven to 200°C.