Place squash halves, hollow-side down, into a microwave-safe dish; pour in water. Cover with a paper towel or microwave-safe lid.
Microwave squash until tender, about 15 minutes.
Heat olive oil in a skillet over medium heat; cook and stir onion and bell pepper in the hot oil until tender, 5 to 10 minutes.
Add shrimp, corn, and peas; cook until shrimp is is no longer transparent in the center and water has evaporated from frozen vegetables, about 5 minutes.
Season with curry powder, salt, and pepper.
Scoop shrimp mixture into squash halves.