Preheat the oven to 160°C. Take whole wheat flour in a bowl. Add bran, refined flour and mix.
Add chilled butter cut into small pieces and mix with fingertips till the mixture resembles breadcrumbs. Add powdered sugar and mix.
Add cold milk (or water or a mixture of the two) and knead lightly taking care not to overwork the dough.
Sprinkle some flour on the worktop and roll out the dough to one-fourth inch thickness.
With different shaped cookie cutters cut out biscuits. Place the biscuits on a baking tray keeping a little space between each. Bake in preheated oven at 160°C till done. Cool and store in airtight tins.