Prepare the following, adding them to a blender as you complete them: Coarsely chop 1 (2-inch) piece unpeeled ginger. Coarsely chop ½ small shallot. Coarsely chop 1 (6-inch piece) lemongrass. Juice 1 medium lime (about 2 tablespoons).
Add ½ cup vegetable oil, 2 tablespoons chile-garlic sauce, and 2 tablespoons packed light brown sugar. Blend until smooth.
