In a wok or large skillet, drizzle oil over high heat. Add the garlic and ginger. Fry just until fragrant, about 30 seconds. Stir in the pork and cook, stirring often, until pork is heated through.
Stir in the chilies, cook for a minute, then add lime juice, fish sauce, and sugar. Cook until most of the liquid has evaporated.
Stir in the pineapple pieces and stalks of the water spinach. Cook until heated, then add spinach leaves. Cook until leaves begin to wilt and taste for seasoning. Remove from heat and let cool.
Once the pork pineapple mixture is almost room temperature, fill a large pan with hot water. Submerge a rice paper in the water until just softened, 5-10 seconds, lift to remove excess water, and place on work surface. Put 1-2 tablespoons filling near the edge closest to you in the center. Top with a few cilantro leaves.
Fold the sides of the rice paper over the filling, then fold over the edge closest to you to enclose it. Continue to roll to the other side. Repeat with remaining wrappers and filling.