Can I boil lentils and feed to my fish?
Is this a good idea?

they dont like spinach and broccoli.. they eat only beans and peas. thats not a good variety...

Which kind of lentils were you thinking? Here's a list of stuff to
try: lettuce (darkleaf), spinach, cucumber, zucchini, oranges,
apples, grapes, bananas, watermelon, pineapple, tangerines,
peas, dehydrated seaweed, shrimp, krill, bloodworms, earthworms
(put in paper towel for 2 days to purge the dirt out of their system).
Plus they may like some other things you'd never think of.

ehmm... i dont know .... the usual lentils.. the ones we eat. u know.. small ound brown..

I'm not sure how high the starch content is in them. So, I
would hold off on them unless someone knows otherwise.

They are full of simple and complex carbohydrates. You could probably feed them very very occasionally - like brown rice - but I would not make it a regular thing; the fishie's tummies will probably not handle them overly well.

oh... no reason to feed 'em then... there are plenty of other things to try