Section citrus (and any other juicy fruits) over a bowl or parchment paper and return the juices that collect to the recipe in some way. Here, the tangerine juices become an ingredient in the vinaigrette.
Wash and dry the endive and arugula and place in a serving bowl.
Over a small bowl and using a sharp paring knife, carefully remove each section of tangerine, cutting between the membranes. Add the sections to the greens. When all the sections have been removed, squeeze the membranes over the bowl.
Whisk in the vinegar and oil and season with salt and pepper. Toss the dressing with the greens and serve.