Steps
1. In a small saucepan over medium heat, combine the shredded beef, black beans, beer, barbecue sauce, and a pinch of salt and pepper.
2. Simmer the mixture for about 10 minutes, allowing the flavors to meld and the sauce to thicken slightly.
3. While the beef and beans are simmering, toast the slices of bread until golden brown.
4. Spread mayonnaise on one side of each slice of bread.
5. Layer the beer-braised beef and bean mixture on one slice of bread, top with cheddar cheese, and garnish with jalapeños or pickles if desired.
6. Close the sandwich with the other slice of bread, mayonnaise side down.
7. Optional: Grill the sandwich in a skillet over medium heat for 3-4 minutes on each side until the cheese melts and the bread is crispy.
8. Slice the sandwich in half and serve hot.