To poach an egg, fill a large, high-sided skillet with water. Add 1 tablespoon of white wine vinegar and bring the water to a gentle simmer over medium-low heat. Crack an egg into a small bowl and then drop it into the water. Swirl a spoon gently around the egg to create a small vortex. Cook for 3 minutes, then remove with a slotted spoon and dab gently with a paper towel to remove any excess water.