Can I sue if a roach was in my food I was eating

If it happened while at the restaurant and you reported it immediately, there is certainly a claim to be made, though litigation may or may not be appropriate, depending on the details. If this was claimed to be found with take out, you can try to make a claim, but in many instances they are sumarily denied unless you can prove the roach came from there. You can always call the health department and if thier inspection reveals roach issues, that might help your claim.