Poached Egg with Miso

Pour vinegar into a small bowl. Crack egg into the vinegar and let sit 5 minutes. Bring a small pot of water to boil. Using a whisk or wooden spoon, swirl water around the edge of the pot until a vortex forms in the center. Slip egg with vinegar into the vortex and continue to swirl water until it returns to boil. The egg white should have wrapped around the yolk by now. Reduce the heat and gently simmer egg. Keep swirling the water frequently, for about 2 minutes. Using a slotted spoon, transfer egg to a small bowl. Mix miso and hot water, pour over egg. Sprinkle green onion on top. (Optional) Add few drops of soy sauce and/or sesame oil before serving.