Begin by cooking the quinoa according to package instructions.
Heat the extra-virgin olive oil in a frying pan and add the thawed barramundi fillet to the pan. Cook for 4 minutes, before turning it onto the other side and cooking it for another 4-5 minutes.
In the meantime, assemble the Rainbow Slaw by adding the rocket, carrot, zucchini, red cabbage, and parsley to a bowl. Drizzle with extra-virgin olive oil and the lemon juice and stir to combine.
Once cooked, stir the quinoa through the slaw.
Transfer the slaw to a plate and serve alongside the cooked barramundi.