Prepare your steamer, with a heatproof trivet on the bottom of a large pot big enough to accommodate a lipped plate or flat bottomed bowl that you will use for both steaming and serving. Make sure your dish is well above the water level and that a lid will fit on top of the pot. See notes below for more information on steamer set ups.
Set a large saute pan on medium heat and add 1 teaspoon of the oil. Add the spinach and stir fry until the stems are tender and bendable, about 5 minutes, adding 1 teaspoon of soy sauce about half way through. When tender, remove the spinach from the pan, roughly chop on a cutting board, and set aside nearby. You will use this pan again.
Carefully remove your tofu from its packaging (see notes below for handling tips) and place the entire block onto the dish you will be using for both steaming and serving. Using a butter or table knife, gently cut the tofu, while it is in the dish, into 1” slices, and if you have room in your dish, gently push the slices over to fan out a bit.
Place the dish containing the tofu into your steamer set up (making sure you have put water in the bottom of the pot), put the lid on your pot, and turn the heat to high. Steam for 10 minutes. After ten minutes, turn off the heat, leave the pot where it is and put the chopped spinach on top of the tofu to warm, keeping the lid on top. You will notice liquid has seeped out of the tofu and this will be removed before serving.
Put the remaining soy sauce into a small cup with the sugar and give it a little mix so the sugar starts to dissolve; set aside.
While the tofu is steaming, using the same saute pan you already used, set on medium heat, add the remaining oil (5 tsp), and once hot, add the ginger and let it frizzle for about 4 minutes, stirring frequently with a wooden spoon to avoid too much sticking. Then add the white parts of the green onion and the cilantro stems and stir fry for another 2 minutes or so, then finally add the rest of the green onion for another 3 minutes. Add the cilantro leaves for a final minute, then add the soy sauce sugar mixture and mix thoroughly.
Using a spoon or a turkey baster, remove the tofu liquid that has accumulated inside the steaming/serving dish and discard. Lift your bowl gently out of the steamer, mound the fragrant greens on top of the spinach (that is already on top of the tofu) and if you like, add a few more extra teaspoons of soy sauce to the bottom of your dish to add to the juices collecting there. Serve with rice on the side, dig in, and enjoy!