Sure, they make a great side dish with roast beef, but they're also a great dish just on their own. I use small white pearl onions that come in a bag. I hear Trader Joes also sells some multi-colored pearl onions, which would be interesting.
Blanche the onions in boiling water for about a minute, rinse in cold water, then chop the pointed end off and slip off the peels.
Sautee in a half a stick of butter until lightly browned, add 2 cups of chicken, beef or vegetable stock, salt, and a teaspoon of brown sugar.Cover and simmer slowly for 25 min.
Take off the cover, boil off the liquid and add another tbsp of butter and cook down on medium heat till the onions are brown and coated with the thickened juices.