Wrap the potatoes in foil and bake until cooked through, 1 hour to 1 hour 15 minutes.
In the meantime, in a large skillet over medium-high heat, brown the meat, about 5 minutes. Drain the liquid from the skillet. Add the black beans, taco seasoning and 1/2 cup water, bring to a simmer and simmer until the sauce is slightly thickened, about 10 minutes.
Remove the potatoes from the oven and unwrap carefully. Cut a slit lengthwise down the center and spoon out a bit of the potato from the interior of each. Divide the beef and bean mixture among the potatoes, then top each with 1/4 cup of the shredded cheese. Transfer to a baking sheet and bake until the cheese is melted and bubbling, another 15 minutes.
Put the potatoes on a platter and top each with some sour cream, salsa, red onions and jalapenos, and garnish with chopped cilantro.