For the dough
2 C AP flour
1/2 t salt
4 T oil
4 T + water
1 t oil
Mix the flour salt and oil in a bowl until it forms small pea like clumps. Then mix in the water slowly until it forms a stiff ball. Turn out onto a floured surface and hand kneed for 7 minutes or mix in a KitchenAid for 2-3 minutes. Lightly cover the ball with the 1 t oil and wrap tightly in plastic wrap for 30 minutes to rest at room temperature. This would be a good time to make your samosa filling.
Roll the dough out into a snake and divide into 8 even balls. On a floured surface roll each ball into a 7 inch round. Cut each round in half. Fold the semi-circle in half and use a little water to join the flat edges together. Now you should have a little cone. holding it in a loose fist. Fill it almost full, this will take practice to get right. the dough will stretch a little bit, but it will tear if you stretch too far. Use a little more water to seal the top of the cone closed. I like to use a fork to crimp the seams. This seems to work pretty well. Once it is sealed let them sit uncovered for a few minutes for the extra water to dry up and the seam to become well bonded.
Heat 3 inches of oil in a large pan to 325F you'll need a thermometer for this. If you just wing it you might end up with overly browned samosas. To test the oil take a small peice of bread and throw it in to pot it should be hissing and slowly turning brown over 40 second, if it's not hissing the oil is too cold and if it is browns faster then that the oil is too hot.
Cook samosas in small batches so you don't drop the heat of your oil too much, this will make for less oily samosas. Turn them frequently until they are golden brown. Remove to a paper towel to drain. Serve hot or at room temperature.