A: Start with thinly sliced onions and olive oil in a saute pan on medium-high heat. You want a big pan so the onions have room to do their thing. And make sure you have plenty of sliced onions -- two or three cups. They're going to shrink down significantly when caramelized.
Then hit them with some salt. This will draw out the moisture. As they cook, they'll first get soft, then juicy. Then, this concentrates and they begin to brown, or caramelize, making them sweet and delicious. It will take a while, like 10 to 15 minutes.
Stir occasionally and enjoy the process. Give the pan a shake every once in a while. Feel free to add some water to help release those caramel-colored bits of goodness on the bottom of the pan. Keep going until the onions are tender and a deep golden brown.
If you want to be fancy, add some wine or liquor for extra flavor. Madeira wine or brandy goes well with onions. Always taste what you cook and add some seasoning if needed. Caramelized onions are great on burgers and steaks, as well as in salads and soups.
Following these simple steps will give you an awesome onion garnish that makes everything taste better.