UnicornButtPlug yes to picnic dinner! DC's favourite meal is what we call 'snacky dinner':
Canned pasta shapes (rather sugar-loaded but doesn't have them every day)
Tortilla wrap with ham/salami, apple and cheese (can easily do cheese-free)
Cut up fresh vegetables (usual suspects are carrot, cucumber, pepper, and sugar snap peas)
Done. Happy child, fast meal. DH and I then usually eat later once DC is in bed, giving us more time to prepare something.
People1Pleaser get yourself a slow cooker. Bloody amazing. You probably won't use it in the summer, but can eat a bunch of salads then anyways. Turkey cooks fast in stir-fry, as does tofu. You can get packs of ready-prepared vegetables for stir-fries too, which save a heck of a lot of time.
Spaghetti bolognese is quick too. We use some soffretto mix (chopped onion, garlic, celery and tomato, can buy fresh or frozen), minced meat or quorn, then 1 jar of store-bought sauce mixed with either a can of crushed tomatoes or diced tomatoes. Doesn't take long to cook and there are often leftovers. For added vitamin intake, grate some carrots, parsnips, beetroot and courgette once the meat has browned.
Tuna pasta bake is quick too. Don't bother cooking it - once the sauce and pasta are done, mix them together then shove it under the grill to brown it off. There are nice recipes online for tomato-based ones too.
Home-made pizzas. Get some pizza bases (we use Warburton's GF wraps), shove some tomato paste on them, then add whatever toppings you want. I guess the no cheese doesn't help here. Can you have vegetarian cheese?
Pasta salad is also a winner. Can put anything in it (we usually do tuna, sun-dried tomatoes, cucumber, cherry tomatoes and pepper, but you can put anything it it).
Another trick, if you can bothered, is to prep vegetables the night before so when it comes to cooking on a time limit the next day, they are all ready. I often find that prep takes quite a long time, especially with a DC running around and wanting attention.
BBC have a page on speedy suppers: www.bbcgoodfood.com/recipes/collection/under-20-minutes