In a large mixing bowl add sieved maida/all purpose flour, medium rava, salt, chilly powder, baking soda and crushed cumin seeds. Mix well using your hands. This is just to make sure even blending of spices with flour.
Now add water little by little to the bowl, mixing all the ingredients till you get pliable dough. The consistency of the dough should be same as chapati dough or thicker than that. Do not make it thinner which results in oil oozing out biscuits. Knead well and keep it aside for about 15 mins.
Make 3 equal sized balls out of the maida biscuit dough. Roll one of the balls just like chapati neither too thin nor thick.
Using biscuit roller/cutter or pizza cutter or knife cut the rolled chapati horizontally first, then vertically to make diamond shaped maida biscuits. Remove them on a plate.
Heat oil in a pan or kadai, just check the oil is heated enough, by dropping a pinch of dough in to it, if it raises up to the surface, then it is right temperature for deep frying. Lower the flame.
Drop the diamond cuts in to oil in batches and fry them both sides till they are slightly brown. Remove from oil using perforated ladle and drain them on tissue.
Repeat the process with rest of the dough.
Spicy diamond cuts/maida biscuits/tukadi is ready to be served with evening tea. Enjoy this diwali with these crunchy biscuits.