In a large skillet, cook the snowpeas in lightly salted water until crisp-tender, about 3 minutes. Don't overcook them. They should be hot, bright green, and snap when you bend them.
While beans are cooking, place the sour cream chopped mint and mayo in a food processor or blender and whirl until blended thoroughly.
Arrange the beans on a serving plate and top immediately with the cool mint sauce. Serve immediately.