How to Make It
Preheat oven to 350º. Toss the potatoes in 1/4 cup of the olive oil, 2 teaspoons of salt, and a few turns of black pepper. Distribute evenly on a baking sheet and roast until tender, about 40 to 50 minutes.
In a large saucepan, heat 2 tablespoons of the olive oil. Cook the onion over moderate heat until soft and translucent, about 5 to 7 minutes. Add the garlic, jalapeño, chili powder, cumin, crushed red pepper, paprika, oregano, sugar, salt and pepper and cook, stirring, for 1 minute. Stir in the tomatoes and remove from heat. Blend in a food processor or blender until smooth. Return the tomato mixture to heat and simmer for 20 minutes.
In a large bowl, combine the potatoes, beans, and 1 cup of the sauce.
Wrap the tortillas in a damp paper towel and warm them in a microwave oven until soft and pliable, about 1 minute.
Spread a thin layer of sauce on the bottom of a 9-by-13-inch glass baking dish. Arrange the tortillas on a work surface. Spoon a heaping 1/2 cup of the potato mixture onto each tortilla. Roll the tortillas up and line up in the baking dish. Top the enchiladas evenly with the remaining sauce, spreading. Sprinkle the tops of the enchiladas with the vegan cheese (if using). Bake 15 to 20 minutes, until the enchiladas are hot and the cheese is melted.
Serve warm with vegan sour cream, jalapeños, lime wedges and minced green onions.