01 - Combine beef with yogurt, lemon juice, ginger-garlic paste, salt, turmeric, coriander, and chili powder in a large bowl. Toss thoroughly to coat. Cover and marinate for at least 30 minutes, refrigerating overnight for optimal flavor penetration.
02 - Arrange onions, tomatoes, potatoes, and green chilies at the bottom of the slow cooker insert, creating an even base layer.
03 - Place the marinated beef over the vegetable layer, allowing excess marinade to coat the vegetables.
04 - Sprinkle curry powder (or garam masala), cumin, smoked paprika, bay leaves, cinnamon stick, cloves, and cardamom pods evenly over the beef.
05 - Pour beef broth and coconut milk over the ingredients. Stir gently to incorporate the liquids without disturbing the layered arrangement.
06 - Cover and cook on LOW setting for 8 hours or HIGH for 4 hours, until beef is fork-tender and sauce has achieved desired consistency.
07 - Discard bay leaves, cinnamon stick, cloves, and cardamom pods before serving.
08 - Taste the curry and adjust seasoning with additional salt and pepper as needed.
09 - Sprinkle fresh cilantro over the curry and serve immediately with steamed basmati rice or warm naan bread.