Hawaiian sweet potato salad

1 large potato (white, red or Yukon Gold)
1 large sweet potato, peeled and chunked
1 c corn
1 tsp Dijon-style mustard
2 Tbs fresh lime juice
3 Tbs fresh cilantro, chopped
1 clove garlic, minced
3 Tbs oil
1/2 tsp salt
1/4 tsp. ground black pepper
1 cucumber, halved lengthwise and chopped
1/2 red onion, thinly sliced
1/4 c peanuts, finely chopped

1. Cut potato in half. Place the unpeeled potato pieces into a large saucepan, and cover with salted water. Bring to a boil, turn the heat down and simmer for 10 minutes or until cooked through but firm.
2. Remove potato and peel. Cut into cubes.
3. Add the sweet potato to hot water and cook about 12 minutes or until cooked but firm.
4. Once the potatoes are tender, add corn kernels; cook for 30 seconds. Drain through a colander. Fill the saucepan with cold water and drop vegetables into water. Cool for 5 minutes and drain.
5. In a large bowl, whisk together mustard, lime juice, cilantro and garlic. Slowly whisk in oil. Mix in salt and black pepper.
6. Cut cooled potatoes into 1 inch cubes and add to dressing along with cucumber and red onion. Toss well. Serve at room temperature or chilled. Toss the peanuts in just before serving.