The loose idea behind poaching the salmon is gentle cooking: Rather than throwing it into the fire of a grill or the hot, rippling surface of a sauté pan, it is cooked in liquid below a simmer, which is comparably not that much hotter than the salmon's intended cooking temperature. The flavor doesn't come from caramelization due to high heat but rather the subtle flavor of the poaching liquid. Once it's cooked, Waters suggests making a simple sauce by stirring butter into the reduced liquid and seasoning that with a little lemon juice. Marvelous and simple. I served mine on a bed of egg noodles, though this would be wonderful with rice or simply a salad.