How to Make It
In a medium saucepan, heat the oil. Add the chiles in batches and toast over moderately high heat until pliable and fragrant, about 1 minute. Using tongs, transfer the chiles to a heatproof bowl and cover with the boiling water; set a plate on top to submerge the chiles. Let stand until softened, about 20 minutes. Reserve the saucepan and oil.
Drain the chiles, reserving 2/3 cup of the soaking liquid. Transfer the chiles and their soaking liquid to a blender along with the garlic, oregano and pepper and puree until smooth. Strain the chile puree through a fine sieve. Reheat the oil in the saucepan. Add the chile puree and 3/4 cup of water and cook over moderate heat, stirring constantly, until slightly thickened, about 5 minutes. Season the chile sauce with salt and the sugar.
Add the kale and black beans to the chile sauce and cook, stirring occasionally, until the kale is wilted and the beans are hot, about 5 minutes. Transfer to a wide bowl and sprinkle with the queso fresco. Serve with the warm tortillas.