Preheat the oven to 180C/160C Fan/Gas mark four. Line three baking trays with baking paper.
To make the biscuit dough, whisk the butter, sugar, flour and semolina together in an electric food mixer until a soft dough is formed. Be careful not to over-beat the mixture. Those who do not have an electric food mixer can add the butter and sugar to a mixing bowl and beat with a wooden spoon until soft and creamy. Next, stir in the flour and semolina. The dough should then be divided evenly into three. Dust the work surface with flour before kneading each batch.
Chocolate chip biscuits
Knead the chocolate chips into one portion of dough and shape into 20 balls. Space them well apart and arrange on one of the baking trays. Press down with the back of a fork into round discs about 5cm/2inch in diameter and bake in the oven for 10 minutes, or until the biscuits are a nice golden-brown.
Knead the lemon zest into the second portion of dough. Form this into a long sausage shape (about 20cm/8in long) and roll in the demerara sugar. Cover this in cling film and leave in the freezer for around half an hour, until firm and nearly frozen. Slice into 20 even balls, each about 1cm/½in thick. Space them well apart and arrange on one of the baking trays and bake for about 10 minutes, or until the biscuits are a pale golden-brown.
Knead the almond extract into the remaining dough, with most of the flaked almonds. Shape into 20 balls. Space them well apart and arrange on the third baking tray. Place a few almonds on top of each ball of dough and press flat with the back of a fork into discs about 5cm/2in in diameter. Bake these in the oven for around 10 minutes, until the almond biscuits are a nice golden-brown.