Heat the oil in a large saute pan over medium-high heat. Add the onion and cook until it begins to soften, about 3 minutes. Add the garlic, cumin, salt, chile powder and cayenne and cook until fragrant, about 30 seconds. Add the chiles, beans and broth and bring to a simmer. Cook, stirring occasionally, until the beans have softened and the sauce has thickened, 5 to 7 minutes. Transfer to a serving bowl and sprinkle with cilantro leaves and Cotija.