Wash 3 green capsicums and cut off their tops. Remove the seeds and white membranes, keeping the capsicums whole for stuffing.

Boil 3 medium potatoes until fork-tender, about 12 to 15 minutes. Drain the potatoes and let them cool slightly.

Peel the cooked potatoes and mash them in a mixing bowl until mostly smooth. Leave a few small pieces for texture.

Add 1/2 cup onion and 1/2 cup fresh coriander to the mashed potatoes. Mix until the vegetables and herbs are evenly distributed.

Season the filling with 1.5 tsp chilly powder, 1 tsp ground turmeric, 1.5 tsp ground cumin, and 1.5 tsp ground coriander. Mix thoroughly.

Add 1 tsp dried oregano, 1 tsp black pepper, 1 tsp chaat masala, and salt to taste to the filling. Mix until the spices are evenly incorporated.

Fill each prepared green capsicum firmly with one-third of the potato mixture. Replace the capsicum tops if desired.

Heat 1 tbsp cooking oil in a covered pan over low-medium heat. Place the stuffed capsicums in the pan with the open side facing upward.

Pour 1/4 cup water around the capsicums and cover the pan. Cook for 10 minutes over low heat until the capsicums begin to soften.

Turn the capsicums carefully onto their sides and cover again. Cook for 10 to 15 minutes, turning once more if needed, until soft and lightly browned.

Transfer the cooked stuffed capsicums to serving plates. Garnish with 1/4 cup cheese and 1/2 tsp chili flakes before serving hot.