Usually when an Indian recipe calls for golden brown or caramelized
onions, the onions are browned in a fairly large amount of oil. Here
is a method requiring very little oil using a non-stick pan.

Slice the onions into very thin, even slices or chop the onions into
small uniform pieces. heat about 1 tablespoon of oil over moderate
heat. The amount of oil depends upon the amount of onions to be
cooked. Stir the onions for 2 minutes. Reduce the heat to low. Add
about 2 tablespoons of water and continue cooking, stirring
constantly. If cooking large quantities, add additional water 1
tablespoon at a time if the onions begin sticking to the pan or fry
too rapidly. This allows the natural moisture of the onions to be
coaxed out while browning. Continue frying until the onions are
golden brown. This process can take about 20 minutes. When simmered
slowly, the onions add a rich dimension and melt into the sauce,
thickening it as well. Brown fried onions can be prepared in large
quantities and refrigerated or frozen and defrosted when needed. Once
defrosted, they cannot be refrozen so it is best to package them in
small quantities.