Prep: Preheat the oven to 425F and grease or line a large baking sheet. Set aside.
Coat the Tofu: Tear the tofu into bite-sized pieces (or cut into cubes) and place in a large bowl. Drizzle the oil over the tofu and stir well, then sprinkle the cornstarch, cajun seasoning, nutritional yeast, and salt on top. Toss well, until all of the tofu is coated; transfer the tofu cubes to the baking sheet individually. If there is any leftover spice blend in the bowl, leave it and use it on the potatoes.
Potatoes: Add the potatoes to the same mixing bowl and top with 1 tablespoon of oil, 1/2 tablespoon cajun seasoning, and a generous pinch of salt. Mix well, then transfer to the other half of the baking sheet.
Bake: Place on the top rack of the oven and bake for 20 minutes.
Veggies: Add the peppers and onion to the same bowl and toss with a pinch of salt and the remaining teaspoon of oil, adding more if necessary. Remove the baking sheet from the oven and flip the tofu and potatoes. Pour the veggies over the potato half and mix them in a bit.
Final Bake: Return the baking sheet to the oven and bake on the top rack for a final 20 to 25 minutes, until the bell peppers are tender. Remove from the oven and mix everything together well. Sprinkle with parsley.
Serve & Store: Serve warm, as-is or over brown rice. Store leftovers in the refrigerator in an airtight container for up to 5 days.
Cajun seasoning: I used this recipe to make some homemade cajun seasoning. If you go with store-bought look for salt-free, otherwise the recipe will be too salty. If your seasoning blend has salt in it I would omit the salt and start with ½ tablespoon and adjust from there