Take flour, salt, baking soda and refined oil or ghee in a bowl. Knead all the ingredients with the help of water, to make a smooth but firm dough.
Cover the dough and set aside for 30 minutes.
Wash and peel one large potato.
Now cut the potato into small cubes.
Heat 2 tsp refined oil in a pan.
Add whole cumin seeds and one dry red chili.
Wait for 10-15 seconds, then add ginger paste and saute for 10 seconds.
Now add cubed potato, coriander powder, red chilli powder, tsp turmeric powder, salt, tsp sugar (optional), chopped green chili and 1tbsp water, mix them well. Cook covered all the ingredients on low flame for 8-10 minutes.
After 10 minutes when the potato cubes becomes soft, add garam masala powder and chopped coriander leaves.
Mix well and turn off the heat. Allow it to cool.
Now after 30 minutes divide the dough into 2 equal portions.
Add a pinch of green food colour with one portion and knead well.
Now divide each portion into 2 equal dough.
Take one white dough, make a ball and flatten the dough.
Sprinkle flour and roll out the dough in oval shape with the help of rolling pin.
Now cut the rolled dough into halves with the help of a knife.
Keep those dough pieces aside.
Now take one green dough and also roll out with the help of a rolling pin and cut it into halves.
Now make small round holes all over the green pieces.
Now apply water with a brush on one side of the perforated green piece and place one white piece over the green piece.
On one side of dough, apply water, join two edges to make a cone and press gently to seal the cone.
Fill the cone with stuffing, apply water on the edges and bring the edges together and seal them properly.
Follow the same process with the remaining dough.
Now heat oil in a pan and deep fry the samosa's on low flame till golden brown in colour.