There is this handy feature that our oven has where you can program it to bake. I'm finding this a useful luxury now that I'm a strapped for time working mom. It's no good for meats because you must be able to leave what you're baking/roasting in the oven all day, but it's particularly useful for roasting vegetables. It typically takes 40 minutes to properly roast potatoes/sweet potatoes, so I wash, cut and season my potato wedges in the morning and pop them in the oven to begin roasting at 4:30pm. By the time we get home and the rest of the dinner complete, we have perfectly roasted potatoes/sweet potatoes. Potatoes are very forgiving and if they are ready just a little early, the oven also has a 'hold' feature that keeps food warm without over-cooking and drying out (great for keeping deep fried food in limbo while you work in batches).
That said, I was trying a new roasted sweet potato spice blend from 'Mad Hungry' with a combo of brown sugar, salt, cumin and cayenne to eat alongside our old fashion cheeseburgers. I made so many sweet potatoes that we had a ton of leftovers that I decided to make a quick Roasted Sweet Potato and Chipotle Soup. I altered it based on, you guessed it, this handy Everyday Food recipe (published December 2009) by holding back on the spices and seasoning since the sweet potatoes were already seasoned. Once complete a dollop of sour cream adds richness and a velvety texture. This is a wonderful & warming middle of winter soup.