Heat a large frying pan over a medium to high heat with the light butter. Add the beef and brown for a few minutes until nicely coloured on the outside, working in batches if needed. You don't need to cook it through. Transfer to the slow cooker. Optional browning: Browning the beef and softening the onions before slow cooking adds extra depth of flavour, but you can skip these steps for a quicker, dump and go version. Simply add all the slow cooker beef ingredients directly to the slow cooker and cook as instructed. This method hasn't been separately tested.