Heat the oil (or water/broth) in a large, deep skillet over medium heat. Add the onion, peppers, and zucchini. Sauté the vegetables, stirring often, for 5-6 minutes, or until the onion is clear and soft. Add the garlic and sauté for one more minute, stirring constantly.
Reduce the heat to medium low, then add the tofu, quinoa, nutritional yeast, turmeric, oregano, salt, and pepper. Stir everything to combine well. Add the baby greens, if using, and continue cooking the scramble, stirring it gently, until the greens are tender and wilted (about 3 minutes). Stir in the lemon juice, taste the scramble, and add salt and pepper as needed. Serve with any toppings of choice alongside fresh fruit, toast, or any accompaniments you like.
Leftover scramble will keep for up to four days in an airtight container in the fridge.