Roast crayfish heads at 180°C for 20 minutes or until lightly caramelized and aromatic, reserve for stock.

Heat sunflower oil over medium-high heat in small stockpot, then add vegetables and spices to lightly brown, add roasted crayfish heads, add water to cover, place over medium heat and simmer for about 1 hour or until flavors are combined, taste and adjust as needed, pass through chinois.