I'm another me too. A recurring event from my childhood was standing at the register in a store where my mom was waiting for me to pick a candy bar frozen like a deer in headlights. She eventually would say say I had to the count of three or I wouldn't get any, and I would pick at random, and often ended up a little disappointed. Looking back, I may have a solution. I think what kind of sandwich do you want isn't a thinking kind of question, it's a feeling one. I was a very cerebral kid, and tried to analyze everything, but was not really in the world the way some people are. Mindfullness, and sensory and emotional awareness let us know what we like. I was almost 30 before I had any idea that I liked anything other than problem solving reading books drawing and swimming. I knew what i didnt like, but everything else take it or leave it.Im pretty sure those skills can be taught, and the how to make a decision advice is probably inappropriate for this particular kind of situTion. Better is to pick at random, then get him to really pay attention to eating Which ever, and how it makes him FEEL.