Bring a large pot of water to a boil over medium heat, and boil the sweet potatoes until tender, about 30 minutes. Cool and peel the sweet potatoes.
Place the sweet potatoes in a bowl, and mash them with the cream cheese, green onions, chili powder, cumin, oregano, salt, and pepper until well mixed.
Preheat oven to 350 degrees F (175 degrees C), and grease a 13x9 inch baking dish.
Heat the oil in a skillet over medium-low heat, and fry the tortillas, one at a time, for about 30 seconds per side. Remove the tortillas with tongs, and drain on paper towels.
Place about 1/3 cup of sweet potato filling down the center of each tortilla, roll it up, and place filled tortillas seam side down in the prepared baking dish. Pour enchilada sauce over the tortillas, and sprinkle with Monterey Jack cheese.
Bake in the preheated oven for 20 to 30 minutes, until the enchiladas are bubbling and the cheese is beginning to brown.