Chipotle Sweet Potatoes

Saute 3/4 of an onion in olive oil until carmelized. Add lots of water and bring to a boil. Add 4 cubed sweet potatoes. Boil for 15 minutes. Strain and let dry. Saute chipolte peppers in oil until tender. Return potatoes to the pot and remove from heat. Using a potato masher, mash potatoes (!) until smooth. Season and add oil to taste.