Pre-heat the oven to 375°F. Rinse and dry the carrot and celery. Peel and dice the shallot, 2 cloves of garlic, and carrot. Dice the celery. Keep all vegetables separate for now and set off to the side. Put a medium skillet over medium heat and add the pine nuts. Toast, shaking the pan frequently until lightly browned and fragrant, about 5 minutes. Transfer to a plate and set aside.
Put a large skillet over medium-high heat and add the millet. Cook, shaking the pan frequently, until it begins to smell toasted, about 3 to 4 minutes. Add 1 tablespoon of oil, tomato paste, red pepper flakes, and the sugar. Cook, stirring constantly, until the tomato paste is hot, about a minute. Add half of the garlic and half of the shallot to the skillet and cook until fragrant, about a minute. Reserve the rest of garlic and onion for the squash in step 5.
Add the carrot and celery to the same skillet and mix well to combine. Add vegetable powder, a pinch of salt and 2 1/2 cups of water; stir to combine. Bring to a boil, cover, and reduce heat to medium. Cook until the millet is tender and all of the water is absorbed, about 25 to 30 minutes.
While the millet is cooking, rinse and dry the tomatoes. Trim the tops off of the tomatoes and cut them in half. Put them onto a rimmed baking sheet and toss with 1 teaspoon oil and a pinch each of salt and pepper. Roast for about 10 to 15 minutes or until golden brown.
Rinse, trim, and chop the yellow squash and zucchini. Put a medium skillet over medium-high heat and add 1 tablespoon of oil. Cook the remaining shallot and garlic until translucent, about 1 minute, and add the cinnamon, yellow squash, and zucchini. Cook, stirring occasionally until squash is slightly tender, about 6 to 8 minutes. Taste and season with salt and pepper.
Rinse, dry and roughly chop the spinach and basil leaves. When the millet mixture is finished, add the nutritional yeast, basil, spinach and toasted pine nuts. Turn off the heat and let the millet wilt the spinach. Serve millet and roasted tomatoes with the squash.