Prep: Cut the tofu into cubes or triangles. Line a baking sheet or large plate with a paper towel and set aside. Add the tamari, hoisin sauce, vinegar, pepper, water, and cornstarch to a small bowl. Whisk until evenly combined, then set aside.
Fry the Tofu: Cut the tofu into cubes or triangles. Heat a large pan (I used a wok) over medium-high heat and add enough oil to fill the bottom 1/4" of the pan. Once the oil is warm, add the tofu to the pan. Sear the tofu for 3 to 5 minutes on each side, until browned. Remove the tofu from the pan and place on the lined baking sheet. Sprinkle it with salt and set aside.
Mushrooms: Add additional oil to the pan, if necessary. Add the mushrooms to the warm oil and quickly mix so they all are evenly coated, then let them sit untouched in the pan for 2 minutes, to sear. Mix the mushrooms, trying to flip them, and let sit untouched for another minute. Repeat one more time until the mushrooms have drastically reduced in size and are beginning to brown on the edges.
Aromatics: Add the white portion of the green onion, garlic, and ginger to the pan and mix well. Sauté for 1 to 2 minutes, until fragrant, then deglaze the pan with the shaoxing wine (if using). Mix well.
Simmer: Return the fried tofu to the pan and add the broccoli florets. Add the stir fry sauce to the pan and mix well. Bring to a simmer and cook for 3 to 5 minutes, mixing occasionally, until the broccoli is cooked to your liking.
Serve & Store: Turn the heat off and add the remaining green onion; mix well. Serve warm over rice, or as desired. Leftovers will keep in the fridge for up to 5 days.