Onion Thyme Frittata

3 cups finely chopped onion (slightly more than 1 pound onions)
1 tablespoon red wine vinegar or sherry vinegar
3 tablespoons extra virgin olive oil
Salt to taste
2 garlic cloves, minced
1 tablespoon fresh thyme leaves
8 eggs
Salt
freshly ground pepper
2 tablespoons low-fat milk


Place the chopped onions in a bowl, cover with water and add the vinegar. Soak for one hour or longer. Drain, rinse and dry on paper towels. (Note: This step is optional, but the onions will be milder if you do it.)

Heat 2 tablespoons of the oil over medium heat in a 10-inch heavy nonstick skillet. Add the onions. Cook, stirring often, until tender, about five minutes. Add a generous pinch of salt, the garlic and the thyme. Continue to cook, stirring often, until the onions are lightly colored but not browned, about five more minutes. Remove from the heat, and allow to cool slightly.

Beat the eggs in a large bowl. Stir in the salt (about ½ teaspoon), pepper, milk and onions. Clean and dry the pan. Return to the burner, and set on medium-high. Heat the remaining tablespoon of olive oil in the skillet. Drop a bit of egg into the pan; if it sizzles and cooks at once, the pan is ready. Pour in the egg mixture. Tilt the pan to distribute the eggs and filling evenly over the surface. Shake the pan gently, tilting it slightly with one hand while lifting up the edges of the frittata with the spatula in your other hand, to let the eggs run underneath during the first few minutes of cooking.

Turn the heat down to low, cover and cook 10 minutes, shaking the pan gently every once in a while. From time to time, remove the lid, tilt the pan and loosen the bottom of the frittata with a wooden spatula so that it doesn’t burn. It should turn a golden color. The eggs should be just about set; cook a few minutes longer if they’re not.

Meanwhile, heat the broiler. Uncover the pan, and place it under the broiler, not too close to the heat, for one to three minutes. Watch very carefully to make sure the top doesn’t burn (at most, it should brown very slightly and puff under the broiler). Remove from the heat, and shake the pan to make sure the frittata isn’t sticking. Allow it to cool for at least five minutes and for as long as 15 minutes. Loosen the edges with a wooden or plastic spatula. Carefully slide from the pan onto a large round platter. Cut into wedges or into smaller bite-size diamonds. Serve hot, warm, at room temperature or cold.