Other Suitable Vegetables:
Mango, ash gourd, potatoes, eggplant, steamed and chopped arbi/taro root, okra, drumstick (murungakai).
Do not attempt this if you don't have coconut, or green chilies, or coconut oil. They are crucial for an authentic avial!
I like it to have a pourable consistency, but I have noticed some keralite friends make really full of vegetables with very little liquid. I guess one is better for mixing with rice, and the thick one as a side dish. It's delicious either way!