I am currently living with people who don’t eat onions. I was making bitter gourd one morning and I had nothing to fill for a filling. So I chopped up the bitter gourd to make a regular North Indian style vegetable. Since the only thing I found in the pantry was some old celery, I grated that and added it to my sabji.
Voila, a good crunchy onion substitute. I loved it.
I have also tried celery with capsicum and the results are very delicious.