This is the way. Your son has got it down!
My own son is a far pickier eater than me. I will eat anything at all, except jelly which doesn't know whether it wants to be wet or dry. He has ARFID. I had to leave him with a family member for an overnight trip and told them one of the things he will eat was a tin of beans.
What I forgot to mention is that in order for him to eat the full tin of beans they needed to strain the bean sauce into its own bowl, and serve the beans dry.
He is significantly speech delayed so all he kept shouting was I WANT BEAN SOUP, so my family member in a panic started whipping up alsorts of liquefied bean concoctions and when I returned the next day it was like world war 3 had just happened in my house.
She said it was only resolved at 2am where he grabbed her hand, led him to the spoon drawer, chosen the right spoon, placed it in her hand, taken her by the wrist and used her spoon enhanced hand to submerge slightly into the beans until just the sauce had covered the spoon and he scream BEAN SOUP!!!! loud enough to wake the dead.
It made me realise just how rigorously trained he has us all that we think its so normal now that even I forgot to mention it.