Step 1

Have ready 1/2 cup water. If using Chinese brown sugar, put it and 2 Tbs. water in a 10-inch straight-sided skillet over medium heat. Stir frequently with a wooden spoon, chopping up the sugar with the spoon until it dissolves completely, 4 to 5 minutes. (If using white sugar, put it—without the water—in a 10-inch straight-sided skillet over medium. Cook until it starts to melt at the edges and turn golden brown, about 5 minutes.)

Step 2

Reduce the heat to medium low and continue cooking, stirring constantly if using brown sugar or gently swirling the pan if using white sugar, until the bubbling caramel darkens to a reddish brown, 3 to 4 minutes. Remove the pan from the heat and, with your face averted to avoid steam and spatters, carefully pour the 1/2 cup water into the pan. The caramel may harden; if it does, set the pan over medium-high heat and stir until it dissolves. Stir the liquid to blend in the caramel and pour it into a heatproof measuring cup or bowl.

Step 3

Wipe out the pan and heat the olive oil over medium high. Add the shallot and ginger and cook, stirring frequently, until they’re softened and starting to brown, 2 to 3 minutes. Transfer to a bowl.

Step 4

Set the skillet back over high heat. Add the seasoned chicken pieces and cook until they lose their raw color on the outside, about 2 minutes per side; the pan will be crowded and the chicken needn’t brown. Stir in the fish sauce, salt, pepper, chile flakes, and reserved caramel. Reduce the heat to medium and cook at a vigorous simmer, turning the chicken every few minutes, until the chicken is cooked through (cut into a piece to check), about 20 minutes. Stir in the reserved ginger and shallot and cook for 3 to 4 minutes to blend the flavors. Transfer to a serving plate and garnish with the scallion rings.