Bring a saucepan of water to the boil. Add the fresh king prawns and cook for 2–3 minutes, until pink and cooked through. Drain and leave to cool slightly.
Heat the black rice in a frying pan with a splash of water, or microwave according to the packet instructions. Leave it to cool for a few minutes.
Transfer the rice to a large bowl and drizzle over the balsamic vinegar.
Roughly chop the cooked prawns, chop the sun-dried tomatoes, dice the avocado and tear the basil leaves.
Add everything to the bowl along with the olive oil. Season generously with salt and black pepper, then gently toss until everything is evenly combined.
Serve immediately or refrigerate until ready to eat. It's delicious both ways, but I honestly think it tastes even better once chilled.