Hmm, not sure. I always eyeballed it and I never learned officially, so even though such and such amount worked for me it may not be optimized. Probably best to do a search. 
Ful / fool is a middle eastern dish I’ve heard of. Maybe a middle eastern cooking blog will say 🤔 

 Send a pic of your retina, this will help me eyeball it.  I promise no worldcoin.  I'll do some research, I really want to eat this again.  I eat mostly meat nowadays but a savory bean spread is not something I'm willing to give up.