Tip the rice and 600ml water into a pan, then stir in the tomato purée, cumin, chilli and bouillon powder. Cover and cook over a low heat for 20 mins until the rice is tender, and it has absorbed the liquid. Remove from the heat and stir in the black beans.
Meanwhile, mix the tomatoes with the red onion, coriander and the juice of 1 lime to make a salsa. Roughly mash the remaining lime juice with the avocados to create a chunky texture.
Spoon the rice into four bowls or rigid containers (cool the half you are saving for another day first). Top with the tomato salsa, avocado and corn. The rice will keep for up to two days – just make the toppings fresh on the day.
