Easy kids meal with potatoes and veg

Try putting your salmon in foil parcels with some lemon, black pepper and chives, will keep it lovely and moist. You and do similar with any type of fish and change things about adding different flavours.
Marinate chicken breast in yoghurt and a curry paste of your choice then bake or grill.
A bit more expensive but tuna steaks done quickly in a griddle pan are fab, especially with a balsamic glaze at the end.

Another’s really popular, quick and easy one here is chicken breast stuffed with Boursin.

Like you, I don’t like to serve my DC sloppy food all the time because I’d like them to learn how to cut with a knife and fork, but neither do I usually serve ‘meat and two veg’ meals.
Here are some of my very quick and easy dinners which my Dc enjoy:
Potato and pea frittata realfood.tesco.com/recipes/pea-and-potato-frittata.html
Chorizo and spinach frittata realfood.tesco.com/recipes/chorizo-and-spinach-frittata.html
Pork and apple burgers with wedges
Toad in the hole recipes.sainsburys.co.uk/recipes/main-courses/toad-in-the-hole-vegetables
Tuna fishcakes realfood.tesco.com/recipes/tuna-fishcakes-with-salsa-verde.html
Pork schnitzel www.bbcgoodfood.com/recipes/pork-schnitzel
Chicken traybake www.bbcgoodfood.com/recipes/harissa-chicken-traybake-0

I do lots of grilled or fried options with potatoes and veg - last night they had sausages. They both like a lamb chop and I buy those very thin ones that cook super quick and aren't too expensive. Steak goes down well but we only do that very occasionally due to cost. Pork chops are good too. Do a big roast chicken at least once every two weeks and serve it with new potatoes and veg rather than as a big roast. DS, DH and me have leftovers as a chicken salad the next day or sometimes as part of a risotto (dd won't eat either of those. She's a pain).

Agree with a pp re salmon parcels although haven't done those for a while. I do sometimes do frozen cod fillets, defrosted then dipped in egg and flour and fried. Chicken schnitzels go down well too.

I'd absolutely recommend The Roasting Tin by Rukmini Iyer, which is pretty much exactly what you are looking for, and gives cooking times for each option. I tend to use fresh rather than frozen fish, and they don't dry out - tonight I will be having salmon, new potatoes, peppers and broccoli with anchovies, chilli and garlic.

My main go-to oven protein sources are chicken thighs, fresh fish, sausages and tinned pulses.

For non-traybake options, we often have turkey escalopes in breadcrumbs, fishcakes, steak, pork or lamb chops or Swedish meatballs.