For the sauce: peel and de-seed the cucumber then cut into small dice. Peel the shallots and finely slice. Finely slice the red chilli. Place the vinegar, sugar and salt in a saucepan. Heat, stirring until the sugar is dissolved. Boil for 7 minutes until you have a thin syrup. Once cool, add the cucumber, shallots, garlic, chili and coriander. Mix throughly.
Cut the beef fillet into 2cm cubes. Finely chop the lemongrass. Chop the coriander. Peel and finely chop the garlic. Combine the lemongrass, garlic, peanut sesame oil, 5 spice, honey, miso and coriander in a bowl. Add the beef cubes to the bowl and marinate overnight.
Place the beef on skewers and then griddle. Serve with the sauce.
«Add a little more chilli to your sauce for a real kick!»