Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the seitan (or vital wheat gluten), vegetable broth, soy sauce, nutritional yeast, olive oil, poultry seasoning, onion powder, garlic powder, black pepper, and salt. Mix well until all the ingredients are combined and form a dough-like consistency.
Place the dough on a clean surface and knead it for a few minutes to develop the gluten. This will give the turkey breast a firmer texture.
Shape the dough into a log shape, resembling a turkey breast. Wrap the log tightly in aluminum foil, twisting the ends to seal it.
Place the wrapped seitan log on a baking sheet and bake it in the preheated oven for 1 hour. This will help the flavors develop and the seitan to firm up.
While the seitan is baking, prepare the glaze by combining the maple syrup, Dijon mustard, soy sauce, and dried thyme in a small bowl. Mix well until the ingredients are thoroughly combined.
After 1 hour, remove the seitan from the oven and carefully unwrap it from the foil. Brush the glaze generously over the seitan, making sure to cover all sides.
Return the glazed seitan to the oven, uncovered, and bake for an additional 15-20 minutes. This will allow the glaze to caramelize and create a beautiful golden brown color on the outside.
Once the vegan turkey breast is done, remove it from the oven and let it cool for a few minutes. Slice it into thick pieces and serve warm.
This vegan turkey breast makes a delightful centerpiece for holiday meals or any special occasion. Enjoy!