In a small bowl, combine the sugar, minced onion, ground cumin, smoked paprika, garlic powder, salt and pepper.
Brown the ground bison, then stir in the tomato paste, water, and chokecherry juice. Add in the spices mixture and stir into the sauce. Let simmer for 5-10 minutes, giving time for the flavors and spices to infuse into the sauce.
Toast the buns and serve Sloppy Joes. As an alternative, serve over wild rice or zuchinni noodles.