Jacket potatoes are not a short cooking time!
Risotto is actually fairly quick. Fry the rice for a good five minutes and then it is actually done in another 15. I like adding mushrooms and leek and cheese, or leftover chicken from a roast.
We often have sausage bake - chop onions, peppers and potato into slices (the potato needs to be about 4mm thick). Slosh in oil and put the sausages on top. It takes about half an hour at 180 but is so fast to prepare it might be worth it.
Likewise, buy sausagemeat (you can get it as is, or buy actual sausages). Stuff halved peppers with a chunk of cheese and the sausagemeat, and bake for about 20 minutes/half an hour.
Quicker:
Pan-fry slices of aubergine, then (separate pan) slices of halloumi. Bag of watercress or rocket salad, generous drizzle of balsamic glaze, and you're done. It's nice with couscous but also nice on its own.
Quickest:
When the oven's on, stick in a tray of roast veg. Then when you want a quick meal, cook pasta and, as it's cooking, heat up the roast veg with a spoon of soft cheese or a bit of water. Chopped ham is nice to add if you've used veg like tomatoes and peppers.