1. Preheat grill 45 minutes before using. Place cecina and longaniza directly on grill grate and cook for a couple of minutes. Remove from grill and set aside.
2. Chop cecina and slice longaniza. Set aside.
3. In a hot skillet, cook bacon until golden brown and some fat has begun to render out. Add onion and garlic and cook until translucent. Add árbol chile and tomato and cook 5 more minutes.
4. Add pinto beans, pinto bean broth, chopped cecina, and sliced longaniza and cook for a couple of minutes more.
5. Serve charro beans with chile serrano, cebolla, and pork rinds on the side.