Heat the oven to 400F.
Place the potatoes on a large, rimmed baking pan. Drizzle with 2 tablespoons of oil, sprinkle with ¼ teaspoon salt, and toss to combine.
Roast 30-45 minutes, flipping once, until browned on both sides.
Meanwhile, heat an additional 1 tablespoon oil in a large pan or skillet. Add the sausage, if using, and cook on medium-high until browned and cooked through, about 8-10 minutes.
Scoop the sausage out of the pan and set aside, leaving any brown crispy bits in the pan. To the same pan, add an additional 1 tablespoon oil, the onion, and ¼ teaspoon salt, stirring to combine.
Cook over medium heat, stirring occasionally, until the onions are softened and slightly browned. Add the greens and cook until wilted, stirring often. Remove the spinach and onions from the pan and set aside.
If using eggs: Whisk together the eggs with the turmeric and ¼ salt. If using tofu: crumble the tofu and sprinkle with ¼ salt and turmeric.
To the same pan, heat an additional 1 tablespoon oil over medium heat. Add the eggs or tofu and cook, stirring occasionally until cooked through, about 3-4 minutes for the eggs and 8-10 minutes for the tofu.
Assemble the bowls by layering the potatoes, greens, sausage, and eggs or tofu. When ready to serve top with hot sauce, green onions and avocado if you like.
Serve warm, or cool and store in individual servings for 4-5 days in the fridge.