Firm, slightly underripe pears are the ones for this; a ripe pear has nowhere to go and comes out as sauce. Barely cover them with water, keep it under a simmer, and turn them once so they colour evenly.
The method above is what decides the dish, not a step-by-step recipe. The link runs a web search on the name: this page has no vetted sources of its own, and will not invent any.