I stutter on 'lettuce' too, and have found that if I say "tomatoes, lettuce..." rather than the other (more logical) way, I can get it out just fine. Thankfully I like tomatoes too :D I've also found that telling them ahead of time (before topping selections) about the stutter that I get less smirks. Also, pointing helps. ..Stupid pepperjack cheese...why are you so tasty??