Bring a large pot of heavily salted water to a boil. Fill a large mixing bowl with ice water and set aside.
Add the snap pea pods and boil for 2 minutes. With a slotted spoon, remove the pea pods and immediately place them into the ice water to stop the cooking. Allow the pea pods to remain in the ice water for 2-3 minutes and then drain well.
Toss the pea pods with the red onion and kosher salt and pepper to taste. Serve at room temperature or store in an air-tight container for up to 5 days.