Heat a large frying pan over a high heat. When hot, drizzle with oil and add the tofu cubes, arranging them in one layer. Reduce the heat to medium and cook undisturbed for 1-2 minutes or until the bottoms of the tofu cubes are golden. Flip the cubes over and cook until golden on all sides. Transfer the tofu to a plate lined with kitchen paper to drain. Wipe out the pan and add a little more oil, then toss in the onion, chilli, ginger and garlic, and stir-fry for 1 minute until fragrant. Add the cauliflower, season with sea salt and stir-fry for 4-6 minutes, or until the cauliflower is just tender. Add the tofu along with the spice mix and stir to combine. Take the pan off the heat.