Spread out the onions evenly so that they are making as much contact with the pan as possible; sprinkle with salt. (yupitsvegan.com)
With too little oil, heat concentrates where food comes in contact with the pan, causing some parts to scorch while others remain undercooked. (discovermagazine.com)
Cook, pressing occasionally to help meat make contact with pan, until underside is browned and very crisp, about 5 minutes. (bonappetit.com)