Heat the oil in a saucepan and brown the beef in batches. Transfer to the slow cooker.
To the saucepan, add onions and cook until softened. Add garlic, ginger, chillies, cumin, coriander, turmeric, salt, pepper, cardamom and cloves. Cook one minute. Add stock and bay leaf and bring to a simmer.
Pour the onion mixture over the beef and stir. Cover and cook on Low for 8-10 hours or High for 4-5 hours, until beef is very tender.