Remove oil from wok and clean out any residue. Add 1 Tbsp. of oil to pan and heat over medium high heat. Add garlic, ginger, chile de arbol, and white part of scallions. Cook, stirring frequently, until fragrant (about 30 seconds). Add water, sugar, and soy sauce. Bring to boil and cook until sauce has thickened and reduced, about 5-10 minutes.