Take your tofu out of the packet and firmly pat it dry. I have tested this recipe with frozen and defrosted tofu as well as tofu straight out of the packet. I find that frozen and defrosted tofu absorbs a bit more sauce, but it becomes tender and finnicky to slice or cube. If you use frozen and defrosted tofu, I recommend tearing it into chunks.
Whisk all the ingredients for the marinade together except for the oil. Test and check for any flavour imbalances before adding the oil. The oil will sit on top of the marinade and make it a bit harder to taste and adjust, which is why we add it last.
Add the tofu to the marinade, ensuring every piece is well coated. To marinate, we want to make sure the maximum amount of marinating liquid is touching the maximum amount of tofu. My best solution at the moment is to store the tofu in a food safe plastic or Ziploc bag and flip it to distribute the liquid every so often.
Leave the tofu to marinate for 24 hours – I have also left it up to 48 hours and I daresay you could go a bit longer.
When ready to cook, preheat a large pan over a medium heat. Once heated through, add the tofu and be sure to squeeze out all the marinating mixture into the pan.
Cook until the tofu is warmed through and the sauce starts to bubble.
Whisk the cornstarch with the water until all lumps are gone, then pour the mixture into the pan and evenly distribute it. This will thicken the sauce and make it more cohesive.
If you like, drizzle over a teaspoon of gluten free dark soy sauce for a deeper, more mahogany brown colour. Finish with chilli to taste if you are using it (you can also add this to the marinade sauce if you have a good idea of how spicy you like it).