Combine all marinade ingredients in a bowl and mix well.

Place the whole fillet in a large tray. Then use a marinade needle (marinade injector) to inject the marinade into the beef.

Once done, put the whole fillet into an oven bag, along with any remaining marinade. Leave in the fridge for 2 days, turning daily to ensure the meat is marinated evenly.

When ready to roast, put the whole fillet on your spit rod over a low fire. Spit roast for 3-4 hours, basting* with marinade every 2-3 minutes.

Use a meat thermometer to test when the meat has reached a temperature of 75°C.

Serve with a good salad and lots of red wine.

*For the baste, set aside some of the original marinade (stored in a tight container in the fridge) or make some fresh on the day of the roast.