Prepare the broth for the seitan: Fill a stockpot with the water, bouillon cubes, and soy sauce. Cover and bring to a boil. Once it boils, lower the heat to low, just to the point where it's about to boil, but barely simmering. This is key, you don't want a boil when the seitan is added. This will make for a spongey meatball.
Meanwhile, mix together the gluten flour, nutritional yeast, italian seasoning and black pepper in a large bowl. In a large measuring cup, mix together the broth, soy sauce, olive oil, and garlic. Pour the wet ingredients into the dry and stir with a wooden spoon until most of the moisture has been absorbed and the wet ingredients are partially clumped up with the dry ingredients. Separate the dough into 48 pieces. Using your hands, knead each piece until smooth and elastic then roll into a ball.
Once the broth is ready, drop meatballs inches Partially cover the pot and simmer for an hour. At this point they're done, but I like to pan fry them a bit to brown the outsides, but it's not necessary.
For the Sauce: Heat a large skillet over medium heat. Add the olive oil, garlic, basil, and red pepper flakes. Saute until the garlic begins to brown. Add tomatoes. Simmer until the water has evaporated, about 15-20 minutes. Salt and pepper to taste.
To serve, either cook up some pasta of your choice, or make zucchini noodles. Top with a small amount of sauce (you don't need much, the olive oil has been infused with a lot of flavor), and seitan meatballs. Enjoy!