Take whole wheat flour (atta) in a bowl. Add salt, red chili powder, turmeric powder and coriander powder. Mix well.
Add oil and mix till incorporated well using your fingertips.
Now start adding little water at a time and keep kneading the dough.
Keep kneading till you get smooth and tight dough (NOT SOFT like chapati/roti dough).
Cover it with another bowl or plate or plastic wrap. Let it rest for 15 minutes.
After resting time knead the dough once again.
Divide the mixture in 24-25 equal portions, Make smooth ball and then flatten it out between your palm.
Work with one flatten disc at a time. Roll into 2-3 inch diameter circle. It should not be too thin or too thick.
Roll few pooris and keep them in a plate, also keep them covered with kitchen napkin.
Heat the oil in a pan on medium heat. Once hot slice one poori into hot oil.
By very gentle pressing using back of slotted spatula fry them. It will help poori to puff up.
As it is puffed up and bottom side is light brown meaning no more bubbles in the oil.
Then flip it. Fry the other side until it is light golden brown in color.
Remove it from the oil using slotted spoon
Place on paper towel lined plate.
Fry rest of them similarly
Storing the pooris: masala puri are best served fresh. If you are making it for travelling or picnic then Store them in insulated container while it is still warm. If you let it cool completely before storing then it will get chewy.