Peel sweet potato and chop into chunks. Place potato chunks in a microwave steamer, adding enough water to the container to surround the chunks without covering them. Steam the potato chunks in the microwave until they can be easily pierced with a fork (I just set my microwave to the raw vegetable setting). Remove the steamer form the microwave and set aside.
Place the corn in a microwavable dish and microwave until completely thawed and thoroughly heated.
Drain most of the liquid from the steamer, reserving about a tablespoon of the liquid (this makes the potatoes creamier). Mash the potatoes with a potato masher and stir in the corn. Voila! You have a yummy, simple, nutritious, colorful snack! Add a big veggie salad on the side and you have a great, satisfying meal!