2 large sweet onions, halved and thinly sliced
1/2 tablespoon olive oil
1/2 tablespoon butter
kosher salt (black pepper optional)
optional: 1/2-1 teaspoon brown or white sugar
Heat oil and butter in a large skillet over medium-high heat. When butter is melted, add onions. Toss with a spatula until onions are coated in oil/butter mixture. Reduce heat to medium/medium low and stir frequently for about 10 minutes.
Sprinkle with kosher salt (about 1/4 teaspoon) and continue to cook, stirring every few minutes for another 15-30 minutes or until onions are a rich amber color. If desired, add sugar about half way through cooking process. Use to top burgers and sandwiches, add to pizza (seriously, try that pizza- it’s so good), wraps, or dips.
Oven method (works well for larger amounts, at least 4 onions and up to a full pot): Place onions in a dutch oven and toss with oil and/or melted butter. Place lid on oven and cook in a preheated 400 degree oven for 30-60 minutes, stirring every 15 minutes.
You can also put the onions in a crock pot, but to really get them cooked they have to stay in there for a long time, and I like the flavor from a skillet better.