In a bowl, mix yogurt, lemon juice, 1 tsp garam masala, ½ tsp cumin, ½ tsp paprika, and a pinch of salt. Add chicken, toss to coat, and refrigerate 30 minutes to overnight.

Heat 1 tbsp oil in a skillet over medium heat. Cook onion until translucent and beginning to brown (~7 minutes). Add garlic and ginger and cook for 1 additional minute. Stir in remaining spices for 30 seconds to toast them.

Transfer the sautéed aromatics to the slow cooker. Add canned tomatoes, marinated chicken (and any leftover marinade), 1 tsp salt, and 1 tsp garam masala. Stir gently.

Cover and cook on LOW for 4–6 hours or on HIGH for 2–3 hours until chicken is tender and shreds easily.

Remove chicken, shred it, and return it to the pot. Stir in butter and cream over LOW heat until fully melted. Simmer uncovered for 10–15 minutes.

Crush in kasuri methi and adjust salt and lemon if needed.

Garnish with cilantro and a drizzle of melted butter. Serve over rice or with naan.