[Nagoyankee]

You don't need opinions. You need facts.

Onions are a must in curry and anything else is an option. Since the onion pieces almost completely melt while cooking, the curry will look extremely boring if you don't use other ingredients. Therefore, many Japanese use all of the Big 3 that you mentioned (plus one kind of meat).

My question is: Did you like that broccoli-only curry you made? If yes, please forget what I said about onions.