Slice the onions in half from the root to the stem end. Cut off the stem end and remove the peels. Cut the onions into thin slices by cutting perpendicular to the root end to form half moons. The layers of the onions will naturally separate after cutting.

Heat a mixture of half butter and half olive oil (if you are cooking 2-3 onions, you will need about a tablespoon of each) in a large, heavy-bottomed skillet over medium heat until the butter is melted and the oil is shimmering.

Add the onions to the pan, stirring to coat in the fat. Evenly distribute the onions across the bottom of the pan.

Allow the onions to cook, stirring every few minutes. Try not to stir too often, though. Keep an eye on onions – you want them to slowly soften and caramelize, but not brown as you would with sauteing. Reduce the heat to medium low or low as needed.

After the onions have started to soften and turn translucent, season with a pinch of salt. Continue to cook, stirring only occasionally, anywhere from 20-40 minutes, until the onions are very soft, have reduced in volume, and are a deep caramel color (but not burnt).

If desired, deglaze the bottom of the pan with a splash of red wine vinegar or balsamic vinegar if the onions start to stick.

Use as a topping on pizza, burgers or brats; in french onion soup; mix into pasta or risotto; add to quiche, etc.