Edit May 17, 2012: I have since learned that I can no longer tolerate produce that are treated with ethylene gas, as most potatoes are. If you have a corn allergy, please make sure that the potatoes you select and use for this recipe are safe for you.
I roast a tray of organic beets, parsnips, turnips, onions, at least a bulb’s worth of unpeeled garlic cloves, and two whole jalapenos every week. Everything is scrubbed, sometimes peeled and roasted. I cut things up if I am running out of time and need them to cook faster, but they are better whole. No seasonings. Sometimes I toss them in olive oil if I am going to roast them uncovered. We eat any leftovers during the week. The garlic comes out like candy.
I found a great deal on some organic small red potatoes recently and was roasting them in 5LB batches. I simply quarter them, toss them in olive oil and sprinkle with salt prior to roasting. I let them cool and put them in gallon ziplock bags in the freezer. It makes having roasted potatoes quick and easy.
Fennel is wonderful when it is roasted. Cut off the tops and quarter the bulb/root. Drizzle with olive oil and top with minced garlic, fresh ground pepper and salt. I usually cook it ~400 degrees (F) for ~60 minutes. The fennel tops are great baked with fish/olive oil/garlic. Do be very careful that they haven’t coated it with a bunch of junk, though.
Here is a link I found on another forum about roasting veggies.