Marinate the Chicken: In a large bowl, whisk together the Greek yogurt, ginger garlic paste, lemon juice, Kashmiri red chili powder, garam masala, cumin, turmeric, and salt. Add the chicken pieces and toss until every piece is thoroughly coated. Cover and refrigerate for at least 30 minutes, or up to 8 hours — the longer the better for that signature tandoori tang.

Sear for Char (Optional but Worth It): Set the Instant Pot to Sauté on high. Add the avocado oil and, working in two batches, sear the marinated chicken for 2–3 minutes per side until it picks up lightly charred edges. This step mimics the tandoor's smoky char. Remove the chicken and set aside; turn off Sauté.

Pressure Cook: Pour ¼ cup of water into the Instant Pot and scrape up any browned bits from the bottom (this prevents the burn warning). Return all the chicken to the pot. Lock the lid, set the valve to Sealing, and pressure cook on High for 8 minutes, followed by a 5-minute natural release, then quick-release the rest.

Reduce the Sauce: The chicken will release flavorful juices. Set the Instant Pot back to Sauté and simmer for 4–5 minutes, stirring, until the sauce thickens and clings to the chicken pieces. You want a juicy coating, not a pool of liquid — lettuce cups can't hold soup. Check that the chicken reads 165°F (74°C) internally.

Make the Cucumber Raita: While the chicken rests, stir together the Greek yogurt, squeezed-dry grated cucumber, cilantro, mint (if using), ground cumin, salt, and lemon juice. Taste and adjust salt and lemon — it should be cool, fresh, and tangy. This keeps in the fridge for up to 4 days.

Assemble and Serve: Lay the lettuce leaves out on a platter. Spoon 3–4 pieces of tandoori chicken into each cup, drizzle generously with cucumber raita, and top with red onion slices, fresh cilantro, and a squeeze of lemon. Serve immediately while the chicken is warm and the lettuce is crisp.