Many, many thanks to Christine at The Perky Poppy Seed blog for discovering that radishes roast so beautifully. As she says,
When you roast a radish something happens to that in-your-face-bold radish taste. The radish becomes an elegant vegetable, with a mild delicate taste. Roasted radishes are lovely on their own or in a salad. I like mine on top of a spinach salad with a bit of of lemon zest and a nice simple vinaigrette.
After reading her post, I bought 3 bunches of radishes (on sale—extra bonus), roasted them, and they were delicious! I had no idea that your could roast radishes and, probably, daikon as well.
This blog has her recipe, adapted from The Silver Palate cookbook, and her lovely photos. (Stars are mine.)