Heat oil in a large nonstick skillet over medium-high heat. Add onion and curry paste to pan, and sautÃ© 1 minute, stirring occasionally. Stir in sugar; sautÃ© 15 seconds. Add shrimp; sautÃ© 3 minutes or until shrimp are done, stirring frequently. Stir in coconut milk and fish sauce; cook 30 seconds or until thoroughly heated. Remove from heat; stir in green onions and basil.