First of all for stuffing, heat butter then add onions , capsicum, green chillies and saute it properly then add green peas and cook it for 1-2 minute.
Now turn the heat off, add cottage cheese or paneer, grated cheese, salt, pepper powder, chilli flakes, coriander leaves and mix all the ingredients very well then keep the mixture aside for 10-15 minutes.
For making dough, in a mixing bowl add maida, salt, pinch of pepper powder, oil and mix it well, now add water as per required to make a nice dough like a puri.
Take little dough and roll out thin like a chapatti, now with the help of knife cut it into strips and keep aside.
Now make small balls from the stuffing mixture (if you not able to bind balls then add more cheese) and keep aside, in a small bowl around 1 tbsp plain flour and pinch of salt then add little water, mix it well to make glue (consistency of glue should be very thick).
Take two strips make cross from it, put the stuffing ball at centre, fold the strip from one end, apply little glue fold from other side of strip.
Apply little glue at the both edges of second strip and fold one by one, press it slightly with soft hands, make all the pockets similarly.
Now heat oil for deep frying the pockets flame should be medium to high, put the pockets in oil and fry it until become light golden brown in colour, take them out.
Serve the tempting matar paneer pockets with tomato ketchup and enjoy.