Preheat the oven to 425 F or preheat the air fryer to 390 F.
Toss diced sweet potato with oil, cumin powder, red chili powder, and salt.
Spread in a single layer and roast until fork-tender with lightly crisp edges, about 18 to 22 minutes.
Cool the roasted sweet potato for 10 minutes so it stays firm when mixed.
Prep the chaat components
In a large mixing bowl, combine onion, tomato, cucumber, coriander, pomegranate, and green chili.
In a small bowl, whisk lemon juice, tamarind chutney, chaat masala, roasted cumin powder, black salt, and red chili powder.
Assemble and serve
Add roasted sweet potato to the chopped vegetables and pour over the dressing.
Toss gently until the masala coats the sweet potato evenly.
Fold in roasted chana just before serving to keep the crunch.
Taste and adjust lemon juice, salt, or chaat masala, then serve immediately.
Notes
For meal prep, store roasted chana separately and mix only at serving time.Roasted sweet potato can be refrigerated in an airtight container for up to 3 days.Dressing keeps in the refrigerator for up to 4 days.For a milder version, skip green chili and reduce red chili powder.