Mix the flour with the oil, salt, and cumin seeds and pour water little by little, kneading continuously, till the dough reaches the desired consistency. Set aside
To Make the Stuffing
In a pan, heat a little oil. When the oil is hot, add the chopped onions and saute till they become a translucent brown. Add the ginger-garlic paste to the onions and continue sauteing.
Add all the powdered spices and salt one by one and mix well, till the spices appear and smell cooked.
Finally, you can add the chopped mushrooms and saute well. When the mushrooms are cooked, take it off the flame and cool.
To Make the Samosa
Seperate and roll the dough into chapatti sized balls. Flatten like you would for a chappati and cut each into half.
Into this semi-circle, spoon some filling into the centre and fold over the edges, sticking them together with a little oil or water. Form a triangular parcel with the dough over the stuffing.
Once you have folded all the samosas, you can start deep frying them. Make sure you use a large pan with a lot of oil if you want to fry more than one at a time, as the samosas might stick to the bottom or to each other.
Serve hot and fresh with ketchup or any sauce of your choice.