Bring a large pan of salted water to the boil and blanch the prawns for a few minutes. Drain them and leave to cool.
Add the rice to the boiling water and cook according to the instructions on the packet.
Meanwhile, peel the avocados, remove the stones and dice them into small cubes. Wash the cherry tomatoes and cut them into quarters. Set the dressing aside.
Once the rice has been drained, leave it to cool slightly, then place it in a large bowl and dress with the lemon juice, oil, salt and black pepper.
Add the dressing prepared earlier and the Snack&Mixa cubes.
Keep in the fridge until ready to serve.