1Thinly slice purple cabbage and mushrooms.
2Place the mushrooms in a bowl. Add 3 tablespoons of lemon or lime juice, soy sauce, olive oil and garlic to bowl, and mix well. Set aside.
3Mix the cabbage with the vinegar and sugar. Cover. Set both the cabbage and the mushrooms in fridge to marinate, covered, for at least 2 hours, and preferably overnight. Toss both a few times.
4When ready to serve, whisk the remaining tablespoon or lemon or lime juice with the yoghurt and vegetable oil and season with salt and pepper. If making this salad vegan, mush an avocado and combine with vegetable oil, lemon or lime juice, and salt and pepper (wait until the last minute to do this, and keep in mind that avocado won't keep well in the fridge and discolouration may occur).
5To serve, toss the mushrooms once again and drain the juice from them (save juice and add just a bit of it, to taste, if you want to make salad a bit zestier in the end). Tear the basil leaves and mix with the cabbage. Spoon mushrooms atop cabbage, and drizzle the dressing over the salad (if using an avocado in your dressing, combine avocado with salad, and add up to 2 tablespoons more of citrus juice and vegetable oil. Stir well to combine).