Preheat grill to medium-high. Place the butternut squash directly on the grill, whole. Bake for 20 minutes or until soft enough to cut in half with little effort. Scoop out seeds, and place back on the grill. Cook for about 20 minutes more, turning often until tender when pierced with a fork. Using half of the squash, cut into chunks ½ to 1-inch in size. Place chunks in a medium mixing bowl, and set aside.
Or, alternatively to the grill, Preheat oven to 400° F. Place the butternut squash directly in the oven, whole. Bake for 20 minutes or until soft enough to cut in half with little effort. Cut in quarters, place in a baking dish or large cast iron skillet, and roast for 40 more minutes or until the skin can be easily peeled away from the flesh. Using half of the squash, cut into chunks about ½ to 1-inch in size. Place chunks in a medium mixing bowl, and set aside.
In a skillet, add the oil, and heat over moderate heat. Once hot, add the leek and cook until softened, about 10 minutes. Place cooked leek in a bowl with the butternut squash.
Add corn, paprika, cumin, and basil to the skillet. Cook corn mixture for about 5 minutes. Add cubed tofu, and stir to combine. Cook, stirring frequently, until tofu develops a soft brown crust on some of the sides, about 5-10 minutes. Mix corn and tofu into butternut squash mixture.
Toast the tortillas over a medium grill or on the stove in a dry skillet if desired.
Top the taco filling with Asian-style Salsa (recipe below), sliced avocado, and lime. Enjoy!