To make, cut the roots and tops off of the onions, then cut them in half, then slice “with the grain”, making julienne slices about 1/4-1/8-inch thick.
Turn the heat to medium-low. Over the next 30 minutes, you’ll really begin to see the onions changing color. You’ll want to stir every 3 minutes or so.
You’ll most likely begin to see brown bits on the bottom of your pan now. This is fond and it’s added flavor we want in the onions so just add a small splash of water and scrape it back into the onions.