3 large Vidalia onions — (or other sweet onions such as Walla Walla), large dice 2 tablespoons butter 1 garlic clove — finely chopped 2 tablespoons all-purpose flour 1 1/4 cups milk 1 Pinch nutmeg Salt and pepper 1/4 cup grated Parmesan cheese
Preheat oven to 350 degrees.
Bring a pot of salted water to a boil and add the onions. Boil for 8 to 10 minutes, until very tender. Drain the onions, reserving 1/4 cup of the liquid.
In a saucepan, melt the butter over medium heat. Add the garlic and cook for about 1 minute. Whisk in the flour and cook for 2 minutes, stirring regularly. Slowly whisk in the milk and reserved onion water. Whisk constantly until mixture thickens and begins to boil. Add the onions and nutmeg; season to taste with salt and pepper.
Spoon the mixture into a lightly greased 1 quart baking dish or into 8 individual ramekins.
Sprinkle with the cheese. Bake until the top is lightly browned, about 30 minutes.