Whats The Best Way To Feed Your Fish Veggies?

[gh74]

I was wondering what is the best way to feed fish/clown loaches veggies,i have heard that green peppers they like and wondering do i cut it into small chunks or whats the best way to do it,and would it be the same for all veggies for fish/clowns,all info would be a great help as i know nothing about feeding them veggies.
 
thanks graham