Heat oil in a large, nonstick skillet over high heat. Add onion, garlic, and ginger; cook and stir until fragrant, about 1 minute. Add pork; cook until brown, 7 to 10 minutes. Drain excess liquid from the skillet. Reduce the heat to medium.
Add celery and carrot to the skillet; cook and stir until soft, 2 to 3 minutes. Stir in green onions and soy sauce. Off heat, stir in pine nuts and hoisin sauce; fold in watermelon.
Spoon pork mixture into lettuce leaves; wrap to cover filling. Serve.
Minced Pork and Watermelon Lettuce Wraps · Dinner Match Lab | Dinner Match Lab