Add diced onions and stir using the flat edge of a stiff spatula. The bottom of the onions should begin to brown within about 1 minute.
Reduce heat slightly,continue cooking, stirring often, and allow onions to brown for approximately an additional 4 minutes.
When onions have browned, reduce heat to low and continue cooking until they reach desired doneness.
When onions are done,you can add about 1 tablespoon of water to pan and allow to sit for about 1minute to get all the yummy brown goodness off the bottom of the pan.
Notes
This method takes a little bit of practice before you can get it right every time. The key to success is to have the pan hot enough to brown the onions before they begin to cook. The more the onions cook before they brown the more they will stick to the pan