1. Combine coconut milk, soy sauce and curry powder in a large saucepan. Set aside.
2. Place pork (or beef), scallions, leek, cornstarch, flour, sesame oil, ginger, chile, salt and pepper in a large mixing bowl. Knead by hand until thoroughly combined and the mixture becomes sticky. Divide into 10 equal portions, about 1/4 cup each. Roll each portion into a ball.
3. Heat olive oil in a large nonstick skillet over medium heat, swirling to coat the sides. Add the meatballs and cook, turning occasionally, until browned on all sides, 8 to 10 minutes. Transfer to a plate lined with paper towels.
4. Bring the coconut-milk mixture to a boil over medium-high heat. Add the meatballs; cover, reduce heat to low and cook for 8 minutes.
5. Line a serving bowl with lettuce leaves. Arrange the meatballs on top. Garnish with basil and lemon zest. Serve hot with the coconut-milk sauce drizzled over the top or on the side for dipping.
To Make Ahead: Cover and refrigerate the meatball mixture (Step 2) for up to 2 days.