Wild Mushroom Enchiladas with Ancho Chili cream Sauce

4 servings. Bring 2 cups water to boil in small saucepan. Remove saucepan from heat, add chilies and soak 30 minutes. Drain chilies, reserving 6 tablespoons soaking liquid. Cut stems off chilies. Cut chilies open. Scrape out seeds and discard. Combine chilies, 6 tablespoons reserved soaking liquid and garlic in blender and puree until smooth. Preheat over to 3500 F. Combine cream and chili puree in heavy large skillet. Bring to boil. Reduce heat; simmer 3 minutes. Whisk in lime juice. Season with salt. Strain sauce; return to skillet. (Sauce can be made 1 day ahead. Cover and chill.) Melt butter in another heavy large skillet over medium heat. Add onion and mushrooms and saute until onion is translucent and mushrooms are tender, about 5 minutes. Add cheese, cilantro, tomatoes, and 3 tablespoons cream sauce. Simmer until just heated through, about 4 minutes. Stir in avocado. Season filling with salt and pepper. Remove from heat. Bring remaining cream sauce to simmer over low heat. Cook 1 tortilla in cream mixture until softened, turning to coat, about 15 seconds. Carefully transfer tortilla to baking sheet. Repeat with remaining tortillas. Cover remaining sauce and keep warm. Spoon generous 1/3 cup filling down center of each tortilla. Roll up tortillas, enclosing filling completely. Arrange seam side down on same baking sheet. Cover enchiladas with foil. Bake enchiladas until heated through, about 10 minutes. Transfer to plates. Spoon some sauce atop each. Serve, passing any remaining sauce separately.