In a 4-quart saucepan cover potatoes with salted cold water by 1 inch and simmer 10 minutes, or until potatoes are tender when pierced with a sharp knife.
Drain potatoes in a colander. Potatoes may be cooked 1 day ahead and cooled before being chilled in a sealable plastic bag. Bring potatoes to room temperature before proceeding.
Shell peas if using fresh and trim sugar snap peas. In a large skillet heat oil over moderately high heat until hot but not smoking and sauté all vegetables, stirring frequently, until sugar snaps are crisp-tender and potatoes are heated through, about 4 minutes. Season vegetables with salt and pepper.
