Heat the oil in a large nonstick skillet over medium. Add the frozen peppers and onions (no need to thaw); cook until softened, about 3 minutes. Gradually add the spinach, tossing frequently until the spinach just wilts. Place the vegetable mixture in a colander to drain.
Return the skillet to medium heat. Add the tofu and sprinkle with the nutritional yeast, salt, cumin, and turmeric. Cook until thoroughly heated, 2 to 3 minutes, stirring frequently. Return the vegetable mixture to the pan and stir gently to combine.
