Put the tamari, orange juice, ginger, garlic, honey and chilli flakes in a small saucepan with 100ml cold water and bring to the boil. Cook for 3-5 mins, boiling hard until well reduced, glossy and slightly syrupy. Remove from the heat, pour into a shallow dish and leave to cool.
Thread the beef onto 4 soaked wooden or metal skewers. Place in the marinade, turn and brush until well coated. Cover with cling film and marinate for 30 mins.
While the beef is marinating, prepare the salad. Half-fill a medium pan with water and bring to the boil. Cook the rice for about 20 mins or following pack instructions until tender. Rinse in a sieve under running water until cold, then drain well. Tip into a large bowl.
Add the cucumber, carrots, spring onions, radishes, coriander, mint, oil, lime zest and juice, and toss well together well. Season with a little black pepper. Divide between two plates and top with a sprinkling of nuts and extra herbs to garnish.
Heat the grill to high. (You could also cook the skewers on a non-stick griddle pan.) Put the skewers on a rack above a foil-lined baking tray, reserving any excess marinade. Grill the skewers close to the heat for 3-5 mins each side or until done to your liking. Brush with more marinade when they are turned. They should look sticky and glossy when cooked. Serve hot or cold with the rice salad.