In small bowl, whisk sherry and soy sauce. Set aside.
In wok or large skillet, heat oil over high heat; making sure it does not smoke. Add shallot and ginger, sauté quickly until shallot is tender, about 1 minute. Add lettuce and cook, stirring constantly, until lettuce is wilted, 1 or 2 minutes.
Add sherry mixture. Season with salt, sugar, and pepper. Cook 30 seconds until lettuce is soft. Make sure lettuce stays bright green. Serve right away.