In a large bowl, stir together the whole wheat flour and salt. Use a spoon to stir in the eatable oil and enough water to make a soft dough that is elastic but not sticky. Knead the dough until it is smooth. Divide into 5-6 parts. Roll each piece into a ball. Let rest for a few minutes.
Heat a tawa or skillet over medium heat until hot, and oil or grease lightly. On a lightly floured surface, use a floured rolling pin to roll out the balls of dough until very thin like a tortilla. When the pan starts smoking, put a chapati on it. Cook until the underside has brown spots, about 30 seconds, then flip and cook on the other side. Continue with remaining dough.when all chapati's are made cut each chapati in 4 equal pecies and make or roll it into a cone to put filling in it.
Take a mixing bowl, add boiled mashed potatoes, pinch of chili powder and salt as per your requirement, asafoetida,green chilli, carom seed, Sour Dried Mango Powder and turmeric powder. Mix all the ingredients well and your stuffing is ready.
Now put stuffing into cone prepared before and seal it from all sides so stuffing doesn't spill out while deep frying.
Heat oil for deep frying, for first five minute keep the heat on high so that oil get hot quickly then reduce the heat to medium.
For frying pick up a small batch of the Gujarati Samosa either using hands or a spoon and put them in the hot oil.
Do not put too many samosa's in a single go or else they will not fry properly. Deep fry them in batches in medium hot oil, until nice golden brown and crunchy.
Remove the samosa's from oil when turn brown when the frying sound and the bubbling of oil stops. Place them on paper towels to get rid of excess oil.
Sprinkle chaat masla (if available) over it and serve hot with green chutney.