If you can find the small, flat, yellow- or red-skinned onions sold here as cipolline, by all means use them in this recipe, following the method below.Plus: More Vegetable Recipes and Tips
Using a paring knife, trim the root and stem ends of the onions. In a medium saucepan of boiling water, cook the onions over moderate heat until they are just beginning to soften, about 5 minutes. Drain immediately and peel.
Meanwhile, heat the olive oil in a nonreactive medium saucepan. Add the bay leaves and cook over moderately low heat until fragrant, about 1 minute. Add the onions and cook, stirring occasionally, until just beginning to brown around the edges, about 7 minutes. Add the vinegar, sugar and salt and pepper. Increase the heat to moderate and cook, stirring frequently, until the mixture starts to caramelize, about 2 minutes. Remove the bay leaves. Transfer the onions to a bowl and stir gently to coat them with the syrup. Serve at room temperature.