In a small bowl, whisk together the vinegar, mango nectar and oil.
Place the cabbage and mango in a large bowl. Drizzle the dressing over the top and toss to combine. Add salt and pepper, to taste. Cover and refrigerate up to 4 hours before serving. Toss again just before serving to reincorporate the dressing that has sunk to the bottom of the bowl. Garnish with cilantro, if desired.
Notes
Mango Nectar can be found in your market's juice aisle. Kern's is the brand that I use. It comes in a can (like a soda can).