Bring a large pot of water to a boil. Meanwhile, remove and discard the leaves and core from the cauliflower; cut and separate into small florets. Boil the florets for 2 minutes. Drain the florets well, chill in ice-cold water, and drain well again. Place the garlic, olive oil, vinegar and sugar in a salad bowl and whisk to combine. Add the cauliflower and all other remaining ingredients and toss to coat. Cover and let the flavours in the salad meld in the fridge for 30 minutes. Toss again and serve.