I found this recipe on the A Year of Slow Cooking Website (I just call her the Crockpot Lady). It was great! I think that I would have preferred it to be a little more spicy and a little less orangey (I think it could be solved by adding either a little bit of water, or less concentrate), but it was great nevertheless!
1 1/2 pounds boneless chicken, cut in 2-inch chunks
1/2 cup flour
olive oil, for browning the chicken
1 tablespoon kosher salt (or less)
6 ounces (1/2 can) frozen orange juice concentrate, thawed (I'd opt for little-to-no pulp. The pulp can taste a bit bitter when cooked)
3 tablespoons brown sugar
1 teaspoon balsamic vinegar
3 tablespoons ketchup
Use a 4 quart slow cooker for best results. Dredge the chicken pieces with the flour, and shake off the excess. Go ahead and throw away any remaining flour, we won't need it. Heat olive oil in a large skillet on the stove and brown the chicken on all sides. There is no need to fully cook it, just sear it enough for the flour to stick and get a nice coating.
Plop the chicken pieces into your slow cooker. In a small mixing bowl, combine the orange juice concentrate, brown sugar, balsamic vinegar, salt, and ketchup. Taste. If you'd like the chicken to be a bit sweeter, add a touch more sugar. Pour sauce mixture evenly over the chicken, and toss gingerly to coat.
Cover and cook on low for 6 hours, or on high for 3 to 4. Serve over white or brown rice.