Place the cashews in a small bowl and cover with water. Set aside for 10 minutes to soak.
Remove the block of tofu from the package and rinse with water. Place the block of tofu on a plate and then set a cutting board on top of the tofu. Place something heavy on top of the cutting board, like a few cookbooks or a heavy skillet, and set aside for 10 - 15 minutes while the liquid is pressed out of the tofu.
After pressing the tofu, discard the liquid, then cut the block of tofu in half. Save the other half for another time.
Measure out 1/2 cup of tofu (75 g) by crumbling it into your measuring cup in small crumbles. Set this aside for now.
Discard the water from the cashews and place them into your blender, along with the remaining tofu (not the crumbled tofu that you set aside or the half block you saved for another time), water, lemon juice, nutritional yeast, ume plum vinegar, miso, apple cider vinegar, brown rice vinegar, salt, pepper and mustard powder. Blend until super creamy and smooth, stopping to scrape down the sides of the blender as needed.
Transfer the Dressing to a mixing bowl and add the reserved, crumbled tofu and the parsley and stir until all the ingredients are thoroughly incorporated. Store in your fridge.