In a medium saucepan, saute onions, garlic, and yams in oil of choice for 3-5 minutes, until onions start to soften. Add ground spices, and cook an additional 2 minutes. Pour in broth, stir, and cover with a lid, cooking until yams are soft, about 10 minutes.
Meanwhile, begin enchilada sauce. Heat oil of choice in a small saucepan for 2 minutes. In a small bowl, combine nutritional yeast (if using), cornstarch, ground spices, and pink salt.
After oil is heated, stir this mixture into hot oil. This should create a thick bubbly paste, also known as a roux, which will help thicken up your enchilada sauce. Heat this roux for no longer than 2 minutes, and then add your tomato sauce. You should hear your oil make a frying sound when you add the tomatoes. Stir, and remove from heat.
Once the yams are cooked all the way through, it's time to add ¼ C of that delicious enchilada sauce to your filling mixture. Stir it in and remove the filling mixture from heat.
To assemble, spread about ¼ C of filling onto a flour tortilla- roll and place in a greased 9 x 13 baking dish. I usually line up about 10 in my dish, with each enchilada slightly overlapping the last.
Once your pan is filled, pour remaining enchilada sauce over your stuffed tortillas. Bake at 350º for about 10-15 minutes, until the edges of the tortillas turn golden brown. Top with fresh cilantro, if desired.