Saute the beef and onion in a frying pan or in a searing slow cooker until browned. Add to the slow cooker.
Add the garlic, cumin, oregano, chilli powder, paprika, diced tomatoes, kidney beans, caster sugar, tomato paste and beef stock. Stir.
Cook on low heat for 6-7 hours or on high heat for 4-5 hours.
Taste the chilli with approximately an hour to go and add extra chilli if you feel it needs it (see notes).
Serve with rice, corn chips, grated cheese, sour cream and chopped spring onions.