Onion slices on hamburgers, minced onions on hot dogs or chili, and chopped onions in spaghetti sauce or meatloaf -- these are the ways that many people use onions, in or on something else. Surprisingly, baked sweet onions are a tasty, healthy side dish on their own. Bake them whole, sliced or cut open like a flower blossom to make a simple side dish for meat or poultry dishes, or serve them with a dipping sauce as a tasty appetizer.
Peel the onions and cut off the tops. Discard the peel and the tops.
Place the onions in a shallow baking dish with 1/2 to 1 cup of water in the bottom. Bake the onions, uncovered, at 300 degrees Fahrenheit for 1 to 1 1/2 hours, until the onions are soft when you squeeze them.
Dot the onions with a little butter or margarine and sprinkle them with the salt and pepper. Bake them for 10 to 15 more minutes.
Remove the onions from the oven and transfer them to a serving dish. Sprinkle with balsamic vinegar or grated Parmesan cheese, if desired.