Stir-Fried Water Spinach with Garlic

Look for water spinach (called rau muong or ong choi) in Asian markets. Regular spinach is a great substitute, although it won't be as silky.
Cut the spinach into 3-4-inch-thick pieces. Rinse well and drain. In a large roasting pan filled with water, bring to a boil over high heat. Add the spinach; cook for 30 seconds or until wilted. Drain; rinse with cold water. Strain well.Combine 1 teaspoon butter, oyster sauce, fish sauce, and sugar in a small bowl; whisk to combine. Add 1 teaspoon of garlic. Combine 2 teaspoons of water and cornstarch, stirring with a whisk.Heat the remaining 1 tablespoon of oil in a large skillet or wok over medium-high heat until it is hot but not steaming. Add the remaining 2 teaspoons of garlic; cook for 15 seconds or until fragrant, stirring constantly. Drain any excess water from the spinach; add the spinach to the skillet. Cook for 3 minutes or until fully warmed, stirring constantly. Add the oyster sauce mixture. When the spinach starts to release juice, add the cornstarch mixture. Cook, stirring constantly, for 1 minute or until the sauce thickens and the spinach becomes silky.