Roast half of the duck carcass at 200°C in oven for about 2 hours or until fully browned.

Cover roasted duck carcass with water, then simmer over very low heat for about 6 hours, strain.

The next day, combine the remaining duck carcass with the roasted duck stock, add water as needed to cover, and return to simmer over very low heat for about 6 hours, strain and reserve stock.

The next day, remove fat from stock, add tamarind paste, dried shiitake, lemongrass, and white peppercorn, then reduce over medium heat to light jus texture, taste and adjust as needed, pass through chinois.