meatloaf with wedges (you can hide some veg in the meatloaf mix, maybe, especially if you blitz the meat and veg in a mixer before adding the breadcrumbs and egg, you can also use pasatta as the liquid instead of milk or whatever)
brush chicken drumsticks or thighs with a mix of honey and lemon juice , then roast them. Serve with rice. No sauce just a bit of stickiness and flavour. Also brush chicken bits with marmalade for a sticky coating.
HAve you tried mashing carrots/parsnips into mashed potatoes without telling him, this sometimes works with veg hating children.
Fish finger wraps, everyone else can have salad and salsa with theirs.
Kedgeree
steak sandwiches with frying steak in sub rolls, everyone else could have mushrooms and onions in theirs also.
HM meatballs with spaghetti and grated cheese
(you can hide pasatta and grated onion etc. in these as well)
Will he eat soup if you puree it or is that too much like sauce/gravy?
Jacket potatoes with a hole bored through them, stuffed with a sausage of some kind
mince roly poly, make a suet crust, cook some mince in the usual way, but not too moist, spread on the pastry, roll up and bake. Cut into slices to serve.
Burger squares: make up a burger mix as normal and press it into a lasagna tray. It should be quite thin. Sprinkle the top with some seasoned flour and bake for about 20 minutes. Cut into squares to serve with mash and gravy and veg for those who will eat it.
Chicken breasts stuffed with ham and cheese.
hedgehogs: mash 1lb potatoes with 1lb of cooked veg until smooth then mix in 4oz breadcrumbs and 8oz ready cooked meat of any kind chopped into tiny pieces. Add a couple of tablespoons of milk or stock to help bind it all together. Make the mix into croquette shapes and roll in porridge oats. Bake for 20 minutes until hot and browned. (my kids all love these and don't even realise that there are vegetables in them because there is no evidence of them!)
My AS boys were like this for years. Also their food couldn't touch and they wouldn't eat certain colours of food etc. It does get a bit easier as they grow up and become teenagers. You have my sympathies.