setRelation and callbackColumn

I have a setRelation like this:

$this->crud->setRelation( ‘ingrediente_id’, ‘ingredienti’, ‘{nome} ({um})’ );

This is perfect in the modal insert the dropdown show the nome and um as desired.

But the same appears in the column view where I need to show just name, I tried setting a callbackColumn but anything I try to do except than returning the value make thanother callbackColumn on another field to crash. I get an error 500

Any idea?