Boil the baby potatoes, or halved large potatoes, in salted water until almost tender. Drain well and let them cool slightly before handling.
Lightly grease a baking tray and the bottom of a glass with oil. Arrange the potatoes on the tray, gently smash each one until flattened, then drizzle with a little more oil.
Bake in a preheated 200°C (400°F) oven for 30–35 minutes, or air fry at 190°C (375°F) for 18–22 minutes, turning halfway through, until the potatoes are crisp and golden.
Meanwhile, prepare the yogurt mixture by combining the yogurt, chaat masala, red chili powder, salt, black pepper, cumin seeds, chopped onion, tomato, coriander, and green chili until well mixed.
Spread a layer of the yogurt mixture onto a serving plate, arrange the crispy potatoes on top, then spoon over the remaining yogurt mixture.
Drizzle generously with tamarind chutney, sprinkle with extra chaat masala, garnish with fresh coriander and pomegranate seeds, and serve immediately while the potatoes are warm and crispy.