Preheat oven to 375 degrees F. Place a large skillet over medium-low heat. Add olive oil.
Cook ground turkey in the skillet until almost cooked through about 2 to 3 minutes, breaking it into pieces with a spoon. Add the cubed sweet potato and seasonings, along with ½ cup of water.
Cover the skillet and allow the potatoes to steam for about 10 minutes.
Once the potatoes are soft, remove the skillet from the heat and stir in the black beans. Set aside.
In a saucepan, whisk together all of the sauce ingredients. Set over low heat and simmer for 10 to 15 minutes until thickened.
Add ½ cup sauce to the bottom of a 9 x 13 baking dish. Reserve ¾ cup sauce for the top of the enchiladas and set it aside.
Mix the rest of the remaining sauce into the ground turkey and sweet potato filling.
Shred the cheeses and mix them together.
Working one by one, scoop ⅔ cup of the filling into the center of a tortilla. Top with ¼ cup of cheese. Roll the tortilla and place it seam-side down in the baking dish.
Continue with the rest of the tortillas and filling.
Cover the tops of the enchiladas with the reserved sauce. Then, top with the remaining cheese.
Place baking dish in the oven and bake for 20 minutes, or until the cheese is completely melted and bubbly.
Serve enchiladas warm topped with avocado, jalapeños, and a dollop of sour cream.