First prepare the vegetables. Preheat oven to 400º F.
Cut all the vegetables into manageable chunks, about half an inch to an inch thick, kind of like how you would for ratatouille. Combine all the vegetables with the spices and vinegar in a mixing bowl. Drizzle some olive oil over the top, and mix until everything is well combined.
Place in a roasting pan and roast for about 45 minutes. About halfway through, give it a stir with a spatula so it browns evenly and the tomatoes form a nice juice around the other vegetables. When vegetables are tender and all the juices have blended, stir in the fresh basil at the end, and taste for salt and pepper.
For the teff polenta, bring the broth to a boil in a sauce pan. Stir in the teff with a wire whip and reduce to a brisk simmer, but not a harsh boil. Let it cook for about 15 or 20 minutes, stirring periodically to make sure it isn't burning on the bottom. It will take on the consistency of hot cereal or grits.
At this point, add the hemp seeds, nutritional yeast, and milk, and stir it until it is blended. You can also add the garbanzo beans as well for extra sustenance and protein, and just mix them right in.
Season for salt and pepper at this point. Let it come to a bubble again, then reduce the heat to a low simmer and cover. Let it gurgle like that, covered, on an extremely low simmer for about 10 or 15 more minutes.
Check a couple times to make sure it isn't sticking and burning on the bottom of the pot. It should be creamy but fairly firm when it is ready. Stir in the chopped parsley.
To serve, spoon some polenta into a pasta bowl, and then spoon some of the vegetables on top. Enjoy while it is still smooth, hot, and creamy. It will firm up as it cools down.