Peel the tangerines and slice them across into ¼ inch rounds.
Place them in a large bowl and add the jicama matchsticks, sliced cabbage, and red onion and toss it all together. Whisk the mango purée, lime juice, olive oil, kosher salt, and several generous grinds of black pepper in a small bowl.
Pour the dressing over the slaw and toss to combine. Tightly cover with plastic wrap and refrigerate for at least 4 hours.