Bring stock and water to the boil. Add quinoa, reduce to medium heat (low boil), cover and cook for 15-20 minutes or until cooked through. Set aside to cool.
Combine capers, shallot, garlic, lemon juice and zest, vinegar and 2 tbsp olive oil in a bowl. Whisk until well combined. Season with salt and pepper.
Drizzle chicken with remaining 1 tbsp olive oil and season with salt and pepper. Cook on BBQ for about 7 min a side. Set aside to cool.
Use veggie peeler to slice zucchini into fine strips, discarding stems.
Combine zucchini, rocket, cherry tomatoes and quinoa in a salad bowl, Stir through half of the dressing.
Slice chicken and serve on top of salad, drizzled with remaining dressing.