Place a large, high-sided frying pan or wok over medium-high heat. Add the sugar and 100 milliliters (1/2 cup) water and cook for 5 minutes, swirling the pan occasionally until you are left with a dark caramel. Do not be tempted to stir the mixture.
Add the garlic, chile and ginger and mix through. Pour in 50 milliliters (1/4 cup) water and the fish sauce and bring to a steady boil. Add in the salmon fillets and bok choy, turning to coat completely in the caramel mixture.
Reduce the heat and cook until the salmon is cooked all the way through, 6 minutes. Remove from the heat and garnish with cilantro and drained spring onion curls.
Serve straight away in warmed bowls with warm sticky rice.
Recipe courtesy of Donal Skehan