Brown rice: Rinse with water (or soak overnight), then cook with 1 1/2-2 c of boiling water for 25 minutes (you’ll only need 1 1/2 c if you’ve soaked overnight). Turn off the heat and leave the lid on for a further 5 minutes, then add the salt, stir, and take the lid off to slightly cool while finishing the rest of the salad (you may want to pour into on a flat plate to cool quickly, so it doesn’t wilt the salad when you mix).
Walnuts: Soak the walnuts for an hour in boiling water, or overnight in cool water. Put in a pan on low heat with coconut sugar and salt and lightly toast for 5 minutes until dry and crunchy. Set aside.
Caramelised Onions: Add the onions, vinegar, sweetener and salt to the pan, and heat gently for around 5 minutes, until all liquid has evaporated and the onions are caramelised and soft. Set aside.
Dressing: Blend all ingredients except the oil in a blender until smooth, then slowly add the oil while the blender is running on low to emulsify and thicken it.
Salad: Set some of the large buttercrunch leaves down on each plate (if using). Mix the remaining greens eg rocket and sprouts with the brown rice, 3/4 of the walnuts, onions, and 1/2 c of the dressing, and split between 2 plates. Peel and quarter the feijoas and layer on top, then sprinkle with reserved walnuts, extra sprouts/herbs, and optional cashew parmesan or cashew cheese if desired.