While the chicken roasts, place the onion, tomatoes, garlic, chipotle chile, jalapeno chile, 1 teaspoon of the adobo sauce, cilantro, oregano, and cumin in a blender or food processor and purée until smooth. Heat the canola oil in a large dutch oven over high heat; add the tomato purée and a pinch of salt and cook, stirring frequently until the mixture has darkened in color and thickened, about 10 minutes. Add the broth, black beans, hominy, corn, and shredded chicken and bring to a boil. Simmer until heated through. Taste for seasoning, adding salt, pepper, and adobo sauce if needed.