Heat a large nonstick skillet over medium-high heat. Cook and stir ground beef in the hot skillet until browned and crumbly, 5 to 7 minutes. Remove ground beef to a paper towel-lined plate and drain and discard grease from the skillet.

Return ground beef to the skillet and add black beans, salsa, water, and taco seasoning. Mix well and bring to a boil. Reduce heat slightly and add Cheddar cheese and tortilla strips. Cover and simmer until cheese is melted, about 5 minutes. Top with sour cream.