My son has textural sensory issues and as a result has had a really limited diet for a really long time. Most foods will make him gag and some will make him vomit. He's subsisted on a carb-heavy diet for years, with pancakes and peanut butter sandwiches as his mainstays.
He's almost a teenager, and is finally at a point where he's willing to expand his diet, and we're working with a food therapist. We have been able to add some new foods to his diet with limited success (pasta and sauce, yay!), but we're really hitting a wall with new protein sources. Eggs were a complete fail, as are hotdogs and cheeseburger sliders. He just can't get past the texture, even trying very hard to do so. Processed chicken nuggets have been slightly OK, but less processed (and more chicken-like in texture) nuggets & tenders haven't worked. I think he'd be OK with the texture of fish but he's really put off by the smell and the concept. We do get very fresh fish through our fish CSA so I'm going to keep trying to get him to eat fish. Cheese has been more of a success, although melty/gooey textures don't work for him. So, for example, he can eat pizza with just sauce and then a bowl of shredded mozzarella on the side.
Because the texture of meat has been such a challenge for him, we're looking to find alternate protein sources. I could use some help on ways to prepare tofu, lentils, beans and whatever you might suggest in a way that could appeal to someone with a really sensitive gag reflex. I don't have much experience in cooking tofu. I know that sauces and flavors are often the key to getting people to like tofu but again there's a bit of a wall with him in that area. He likes ketchup and garlic flavors. When we were starting to get him to eat chicken nuggets, we went to McDonalds and I had him try a bunch of their dipping sauces and none of them worked that well, although I think he was less opposed to sweet and sour sauce than the rest. He hasn't been exposed to spicy flavors and I suspect we won't get anywhere in that area, at least not at this point. Things that are gooey, very chewy or very crunchy don't really work well for him (although pretzels have never been a problem and he's recently had some success with cereal, so crunchy may not be completely off the table anymore.)
He won't eat most vegetables either (but we're having a bit more success in that area, so perhaps that will change). He's generally fine with fruits and doesn't have any problem with dairy. There aren't any allergies to contend with, but one of our goals is to get some peanut-free options for an upcoming sleepaway camp where nuts aren't permitted.