1. For the chorizo stuffing: Preheat grill 45 minutes before using. Put a cast iron skillet on the grill and add vegetable oil. Cook chorizo until golden brown. Add onion, garlic, ground beef, tomato, black beans, and yellow corn kernels. Season with salt and set aside.
2. Stuff pasilla chiles with chorizo stuffing and asadero cheese. Grill for 2 minutes or until cheese broils.
3. Garnish cheese and chorizo chiles rellenos with sour cream and cilantro.