Need recipes/tips for super fussy eater

[DinnerNightmare]

DS7 has become super fussy with his food. He used to be a great eater, now everything gets immediately vetoed. I need recipe ideas that a quick and simple (single mum) and meet his approval. I'm vegetarian but am happy to cook meat if he eats it.
Things that he currently refuses to eat:
Anything with sauce (eg Bolognese, curry, chilli...)
Anything that's mixed up (shepherd pie, lasagne... you name, he won't eat it)
Tomatoes, mushrooms, eggs (any kind) - these are things he never liked so I'm letting him off for those
Pasta
Rice
Mashed potato
Baked potato

Things that he will eat:
Boiled or roast potato
Baked beans (sometimes)
Chips
Sweet potato chips
Home made sweet potato Wedges
Chicken nuggets
Sausages
Most veg (apart from tomatoes, mushrooms, Courgette, onions and aubergine)
Standard fruit (apples, bananas, Pear and orange, no others)

Any help greatly appreciated. He loves things like fajitas where he can make his own but invariably he just has raw veg sticks in a wrap if we make them. He won't eat cooked Peppers. 🙈

I'm at my wits end with him.

Hidden veggie sausage rolls
Hidden veg burgers
Sweetcorn fritters and dip
Cheese and ham toastie
Savoury muffins
Mini toad in the hole
Hidden veg and chicken hot dogs
Veg and cheese scones

Thanks @Fivemoreminutes1 some great suggestions there. Actually I think he'd really like the sweetcorn fritters. Could serve them with salad which he does eat for an easy dinner. Sausage rolls sound great too.

Would he eat chicken skewers? Either just chicken breast or a mix of veg and chicken. Chicken can be marinated or coated with something like paprika.
What about fish or sea food?
If mixed up or sauces things are a no go what about a gammon steak with pineapple.
Baked sweet potato with toppings?
Falafel in pita
Chicken marinated in harrisa with cous cous and salad
Stir fry?

Dd has a very similar diet! And I’m also a single mum. What I’ve found that helps a lot is sitting down with her and she chooses her meals for the week. 1 night is takeout/fakeaway and she has to try a new food once during the week (I always serve it with something she likes so it’s not a total disaster).

If I’m not shattered she helps to make her meals, which she feels such a sense of pride about and she will try more I’ve found that way.

What about meatballs - no sauce? Served with boiled potatoes/chips and veg/salad? Small meatballs can just be fried without the need to cook them further in sauce. Something like these Greek meatballs.

Chicken pieces? DD is fussy and loves a nugget/sausage but also likes a chicken thigh that's been roasted/baked (I take it off the bone for her) or a fried chicken breast (I cut large ones horizontally so they aren't too fat) either by itself with veg or as a burger with salad bits on the side.

Similarly, DD likes steak, cooked then cut into strips and I usually do potatoes and boiled veg alongside.

My DD is a fussy eater, but she loves this
www.bbcgoodfood.com/recipes/spicy-black-bean-tacos

Will he eat halloumi grilled in fajita type wraps?
Avocado?

Nut or seed butters on toast. My fussy is allergic to peanut and hazelnut but he likes sunflower seed spread.

I have 3 fussy DC and feed them a pretty basic meat, potatoes and veg diet. Everything plain. I don't hide veg, but they do Ok eating plain vegetables so I make sure they have enough from those. And they are good fruit eaters. Personally I prefer saucy foods, but I'm happy to eat what they eat to avoid food drama, although I will sometimes make a sauce or some gravy to go on mine. If I was veggie we would probably have a lot of quorn and meat substitutes, but one of my DC is allergic to quorn and we are all meat eaters so not a problem in my house.

Broccoli and cashew nuts stir fried with greens garlic and chilli, served with noodles (I’d do it with black bean or oyster sauce but no sauce) - I don’t know why but noodles were considered different to pasta! Takes ten minutes from fridge to plate.

I could’ve written your list, my DS is 7 also.
he eats more processed food than I would like (fish fingers, sausages, waffles). I often make home made potato wedges in the air fryer which take next to no time and ensure he eats a lot of fruit and veg to accompany, which makes me feel he is getting enough vitamins even if it’s not as fresh as I would like. I’m also veggie so don’t want to cook lots of meat.

Another staple is ‘tuna potato’ which is basically baked potato mashed up with tuna with a lot of peas on top.

I make a roast chicken or do (plain)chicken breasts fairly often, again with some sort of potato and a lot of veg.

We make pizzas from scratch sometimes. Not especially nutritious as he just wants ham on, but good to get him involved and have something which isn’t freezer food.

Tonight is meatballs (no sauce), peas, broccoli, potatoes. Other DS and DH will have meatballs with home made tomato sauce with lots of veg in and spaghetti and I’ll have a veggie version.

Not much useful info, but I guess my main point is I’m not overly concerned despite the minutes diet.

Thank you everyone. Some great ideas. Plain meatballs might work. I don't need to hide veg, he's generally quite happy to eat it. It's just what to cook with it. Stir fry wouldn't work as it's mixed together 🙄 I think I'm not concerned about his vitamin intake, just frustrated that whatever I cook, no matter how plain, just gets rejected. I've started cooking separate meals for me because I want to eat something less bland. I do try and make him try new things but it's always such a drama. He ends up leaving it and then eating a banana and some snacks from the cupboard (nuts, rice crackers etc).