01 - Combine beef cubes with yogurt, lemon juice, ginger-garlic paste, salt, turmeric, coriander, and chili powder in a large bowl. Toss thoroughly to coat all pieces. Cover and refrigerate for at least 30 minutes, preferably overnight for deepest flavor penetration.
02 - Arrange sliced onions, chopped tomatoes, cubed potatoes, and slit green chilies evenly across the bottom of the slow cooker insert, creating a solid vegetable base.
03 - Place the marinated beef directly on top of the vegetable layer without mixing, allowing the meat to steam and tenderize properly during cooking.
04 - Sprinkle curry powder or garam masala, ground cumin, smoked paprika, bay leaves, cinnamon stick, whole cloves, and cardamom pods evenly over the beef and vegetables.
05 - Pour beef broth and coconut milk into the slow cooker. Use a wooden spoon to gently incorporate the liquids, being careful not to disturb the layered ingredients too much.
06 - Cover with the lid and cook on LOW setting for 8 hours or HIGH for 4 hours. The beef should be fork-tender and the sauce thickened and deeply aromatic.
07 - Discard the bay leaves, cinnamon stick, whole cloves, and cardamom pods before serving. These have completed their flavor-infusing duty and should not be consumed.
08 - Taste the curry and add more salt and pepper if needed. Garnish generously with chopped fresh cilantro and serve immediately with steamed basmati rice or warm naan bread.