Bring a medium saucepan filled with salted water to a boil.
Add sugar snap peas and blanch 1 minute or until bright green and just tender but still crisp.
Remove peas with a slotted spoon and place into a large bowl with ice water to stop the cooking. Once cool, place on a towel to dry.
Bring water back to a boil and add potatoes, cooking about 5-10 minutes or until a knife can easily pierce through. Drain potatoes and let cool.
Slice sugar snap peas on the diagonal into 2-3 pieces each and place in a large bowl with radishes, potatoes and herbs.
Shake dressing ingredients together in a jar or whisk in a small bowl, then toss with the vegetables. Season with additional salt and black pepper to taste.
Let sit for 10 minutes for flavors to absorb, then enjoy at room temperature or refrigerate for later use.
Optional: for a complete meal, serve on a bed of mixed greens or arugula and top with soft or hard boiled eggs.