Beef skewers with horseradish dip

Method

1. Cut the beef into 2.5cm cubes and place in a freezer bag with the vinegar and 1 tablespoon of the horseradish. Add the rosemary, olive oil, Worcestershire sauce and port, seal and gently shake. Leave in the fridge for at least 20 minutes, but preferably overnight.
2. As you let the meat come to room temperature, soak about 10 bamboo skewers in water.
3. Make the dip by beating together the crème fraîche, the remaining horseradish, mustard, salt and chives, leaving some chives to sprinkle over the top.
4. Thread 3 or 4 pieces of meat onto each skewer and griddle over a high heat for 2 minutes each side. Allow to rest for about 5 minutes and serve, garnished with fresh rosemary.