Caramelize

To convert or change into caramel. This cooking technique is often used for onions, shallots, fennel or others which have a high degree of sugar. The trick is to start with a hot pan. Add a small amount of oil and then your vegetable (in this example, we'll use onions). Allow onions to brown without stirring for a minute or two (this is the sugar changing to caramel), then carefully turn onions so they brown on the other side.