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 30 minutes minimum, or overnight in refrigerator for maximum flavor penetration.
02 - Arrange sliced onions, chopped tomatoes, cubed potatoes, and slit green chilies in an even layer at the bottom of the slow cooker insert.
03 - Place marinated beef pieces on top of the vegetable layer, distributing evenly.
04 - Sprinkle curry powder or garam masala, cumin, smoked paprika, bay leaves, cinnamon stick, whole cloves, and cardamom pods over the beef.
05 - Pour beef broth and coconut milk into the slow cooker. Gently stir to combine without disturbing the layered ingredients too much.
06 - Cover and cook on LOW setting for 8 hours or HIGH for 4 hours until beef is fork-tender and sauce has reached desired consistency.
07 - Discard bay leaves, cinnamon stick, cloves, and cardamom pods before serving.
08 - Taste and adjust seasoning with salt and pepper as needed. Garnish generously with fresh cilantro. Serve hot accompanied by steamed basmati rice or warm naan bread.