In a blender, combine the spinach leaves, coriander leaves, green chillies (if using), and a little water to make a smooth paste.
In a large mixing bowl, add the wheat flour, salt, cumin seeds, and the prepared spinach paste. Mix well.
Gradually add water as needed and knead to form a smooth, pliable dough. The dough should be firm but not too tight. Cover and let it rest for about 15-20 minutes.
Divide the dough into small, lemon-sized balls.
Dust each ball lightly with flour and roll them out into small circles, approximately 3-4 inches in thickness
Heat oil in a deep frying pan over medium heat. To check if the oil is ready, drop a small piece of dough into the oil; if it rises to the surface immediately, the oil is hot enough.
Slide one rolled-out poori into the hot oil gently. Press it lightly with a slotted spoon. The poori should puff up.
Flip it over and fry the other side until golden brown.
Remove the poori from the oil and place it on a paper towel to drain excess oil.
Repeat the process with the remaining dough balls.