Bring a large shallow pan half full of water and a splash of distilled vinegar to a bare simmer; just a few tiny bubbles. Crack an egg into a fine mesh strainer; shake gently to strain off excess liquid. You will be left with the yolk and the bit of the white that will cook solid. Carefully slide into a little prep bowl, give the simmering water a swirl, and carefully slide the strained egg into the water; poach to desired doneness. No more (or very few!) whisps of runaway eggwhite.