Add the onions to the skillet. Add olive oil and salt.
1 tablespoon olive oil, ½ teaspoon salt
Cook on medium-high heat for 3 minutes until the onions begin to soften. Stir them constantly.
Reduce the heat to medium stirring constantly. When the onions begin to brown and the skillet starts building up brown specs, add a splash of water to deglaze it.
1 cup water
Continue stirring and deglazing the skillet until the onions turn deep golden brown in color.
Add the butter and cook for 3-5 minutes. Remove from the heat and store in a glass jar with a lid.
1 tablespoon butter
Notes
This recipe makes about 1 cup of caramelized onions.