In a large, deep skillet or Dutch oven, add the oil and swirl it around to coat the bottom.

Season the chicken thighs with salt and place them skin side down in the cold skillet.

Cook the chicken over medium heat without moving it until the skin turns golden and crispy, about 10 minutes.

Carefully flip the chicken and cook for an additional 1 to 2 minutes until browned on the other side.

Remove the chicken from the skillet and set it aside on a plate.

In the same skillet, add the ginger and garlic, cooking them over medium heat while stirring until they become fragrant, about 1 minute.

Stir in the brown sugar, soy sauce, and ½ cup of water, mixing until the sugar has dissolved.

Return the chicken to the skillet, placing it skin side up.

Increase the heat to medium-high and bring the mixture to a boil.

Once boiling, reduce the heat to medium-low to maintain a gentle simmer, cover the skillet, and cook until the chicken is fully cooked, about 13 to 18 minutes, or until an instant-read thermometer reads 165°F.

Transfer the chicken to a clean plate once cooked.

Bring the sauce in the skillet back to a boil over medium-high heat, then lower the heat to medium-low and let it simmer, stirring occasionally, until it thickens slightly and deepens in color, about 2 to 3 minutes.

In a small bowl, whisk together the cornstarch with the remaining 1 tablespoon of cold water.

Add the cornstarch mixture to the sauce and stir until it thickens to a glaze, which should take about 1 minute.

Return the chicken to the pot and toss it in the glaze to coat evenly.

If desired, sprinkle the dish with sliced scallions before serving.