Remove the frozen puff pastry sheets from the freezer and let them thaw while you prepare the filling.
Heat oil in a pan and add cumin seeds to it. When the seeds start to change color in about 30 seconds, add the diced onions. Cook the onions for 3-4 minutes stirring frequently till they start to turn golden brown.
Add the chopped tomatoes. Cook them for 3-4 minutes, until they form a thick mixture with the onions.
Add the salt, turmeric, red chili powder and garam masala. Mix well.
Add the paneer and mix with the onion tomato masala. Cook for 3 minutes until the paneer becomes soft.
The paneer filling is ready. You can also enjoy this as paneer bhurji or scramble along with roti or naan.
Prepare the Puff Pastry:
If baking in oven, preheat oven to 400°F.
Spread the puff pastry squares on a parchment paper on a baking sheet. Place the paneer filling at the center of the puff pastry square. Make sure the paneer filling is at room temperature when filling in the puff pastry.
Gently fold it and pinch to the other side to make a triangle. All the edges should be closed. Use a fork to seal the edges well.
Beat the egg white. Brush the egg whites on the top side of the stuffed puff pastry. Sprinkle some nigella seeds to get the perfect looking puff!
If using an oven, bake for 12-15 minutes until the paneer puff's are golden browned.
If using an air fryer, place 2 stuffed puff pastries into the air fryer basket. Bake at 390°F for 10-12 minutes. Flip the puffs at about 7 min.
Remove the puff pastries from the oven/air fryer into a serving dish and let them cool for couple of minutes. Enjoy with a dip or chutney and a cup of hot tea.
Notes
For this recipe, you can just mash paneer or just cut it into small cubes.
If you like to skip egg, brush with melted butter or olive oil.
To prepare these ahead of time, stuff the puff pastries and freeze them. When ready to cook, take out of the freezer and let them thaw for some time (not completely to room temperature, we want the puff pastry to still be cool to get a flaky puffs). Brush with egg white and pop them in the oven.