My earlier optimism may not have been entirely justified.
Alex did not do well with the mixed vegetables. At first he refused to eat them. Not an unanticipated maneuver and one I was prepared for.
I popped the first mouthful in and he promptly tongued it back out.
I went to consequences. If he didn't chew and swallow, no more computer. (This technique has always worked better than reinforcers for Alex. Most of the time, he decides what is being offered isn't worth the effort.)
Two mouthfuls and I called it a success. Of sorts. He wasn't happy, having gagged when he refused to chew and tried to swallow a carrot cube whole. But he'd eaten what was asked and now could move on to safer, more familiar foods for his main course.
I probably shouldn't have got my hopes up but he'd been doing so well that I hoped he'd just sail on through.
But in the words of Tim Allen in Galaxy Quest: Never give up! Never surrender! (Autism families should take this as their motto. Except for the fact that we'd probably get sued. And we wouldn't get the funky costumes ... but it's still good advice.)
We've kept on going. Something envelope-pushing has been appearing at just about every supper. Pasta, muffins and mixed vegetables. We will conquer all three. We don't ask him to do a whole lot. 3 or 4 pieces of pasta, a miniature 2 bite muffin and 2 spoonfuls of mixed vegetables. He only faces one of them and only at one meal a day, and not if the meal is already rushed or stressed because of upcoming events (like hockey night).
Eventually, he'll get used to them. I've heard statistics that you have to introduce something a hundred times to overcome a sensory barrier. To be honest, that number seems low to me. But it means we've got a week down and several more months to go before we'll see if we've done it.