Bring 2 cups of water to a boil in a medium saucepan. Stir in dry rice, turn heat to low and simmer for 20 minutes.
Preheat oven to 350 degrees.
Prepare the taco seasoning: combine chili powder, paprika, cumin, ground red cayenne pepper, onion powder, garlic powder, black pepper, and salt in a small bowl and whisk to combine. Set aside.
Heat 2 tbsp of the olive oil in a large sauté pan over medium-high heat. Add diced sweet potatoes and cook for about 8-10 minutes or until potatoes start to soften, stirring occasionally.
Add sliced pasilla pepper and the remaining 1 tbsp of olive oil to the pan and cook for 3 to 4 minutes, stirring occasionally.
Turn heat to medium and stir in taco seasoning and minced garlic. Sauté for 1 to 2 minutes.
Add black beans and cook for another 3 to 4 minutes, stirring frequently.
Remove the pan from heat and stir in picante sauce and lime juice. Add the cooked rice to the pan and stir well to combine.
Lightly grease two 9x13 baking dishes. Pour about ½ cup of Homemade Ranchero Sauce into each baking dish and spread it around evenly.
Prepare the enchiladas: spoon about 1 tablespoon ranchero sauce onto a tortilla, then spread in a thin layer using the back of the spoon. Add about 1/3 cup of the sweet potato black bean filling in a line down the center of the tortilla. Sprinkle with about 2 tablespoons shredded Mexican-blend cheese, then roll up the tortilla and place seam-side down in the prepared baking dish. Repeat until both pans are filled with enchiladas.
Top enchiladas with ranchero sauce: evenly pour about 1 and 1/2 cups per pan over the enchiladas, spreading it with the back of a spoon until fully coated.
Sprinkle the remaining shredded cheese over the enchiladas, about 1 cup per pan.
Bake for 25 minutes.
Serve hot with a side of guacamole and tortilla chips, or let cool and store in an air-tight container for up to 5 days.