Preheat oven to 425
degrees. Peel and cube the sweet potatoes and Yukon Gold potatoes, Scrub
the new potatoes and cut into cubes. Place the potatoes in
a large saucepan. Add enough lightly salted water to cover the
potatoes. Bring to a boil and cook the potatoes for 3 minutes.
Drain thoroughly. Spread the potatoes
in a single layer on a large nonstick baking sheet. Drizzle the potatoes
with olive oil and sprinkle with tarragon, salt and pepper. Roast the
potatoes until browned and crisp, about 25 minutes. Serve immediately.