Around noon I put 2 lbs of oxtails into a pot of boiling water for 30 minutes. Then I drained the water, rinsed the oxtails, and trimmed off the fat of any pieces that had excess. Most were fairly lean, so this was quick work. Then back into the same pot, now empty, along with 2 in of orange rind, 2 star anise, 2 inches of peeled ginger cut into coins, and 1 Tbl. of sea salt, all covered with about 1 inch of water. I cooked this for an hour, then added 1/2 c of raw cashews and covered again for 2 more hours.
At this point in the cooking I would have skimmed off the fat before continuing, but either there was not enough of consequence, or I was hungry and didn't care so I kept cooking. In went 2 cups of chopped and washed mustard greens and 1/4 tsp red pepper flakes, and simmered for about 5 minutes.
The bowls of soup were topped with cilantro, green onions, and freshly grated garlic. The broth made everything worth it, but the greens added at the end created a perfect balance. Make this soup!!!