Begin by removing the tofu from its container and draining or discarding any excess liquid. Place the tofu in a large bowl and use your fingers to crumble it into small, bite-sized pieces. If preferred, you can use a fork or potato masher to assist with this step.
Once the tofu is crumbled, mix in the nutritional yeast, turmeric, cumin, salt, and garlic powder until well combined. These seasonings will infuse the tofu with flavor and color.
Heat oil in a large skillet or wok over medium-high heat. Add the chopped onions and sauté for approximately 3 minutes until they begin to soften and turn translucent.
Add the sliced mushrooms to the skillet and continue to sauté for another 3-4 minutes, allowing them to brown slightly and release their savory flavors.
Next, add the spinach to the skillet and sauté until it starts to wilt, which should take just a few minutes.
Finally, stir in the seasoned tofu, ensuring it is evenly distributed throughout the skillet. Cook for an additional 2-3 minutes, allowing the tofu to absorb the flavors of the other ingredients and heat through.
Taste the mixture and season with black pepper to your liking. Adjust any other seasonings as needed to suit your preferences.