What can I put in the oven with no or minimal effort?

[Blablabla1984]

With the cost of living I am trying to utilize my oven as much as possible and make a few things at a time, rather than just one.

I am just turning it on to make a rice and chicken casserole. Is there anything I can bung in without any or little effort so they cook at the same time?

All I can think of is a tray of frozen fish fingers to have to wraps/sandwiches.

frozen pizza

baked potatoes

All-in-one sponge cake (or sponge pudding if you put the mix over some tinned fruit).

Make larger quantities of what you're oven cooking, then have the extra portions next day or freeze them. This would work well with casserole type meals, then you could heat up the leftovers in the microwave or in saucepan on the stove top.
Or perhaps think about getting an air fryer, actually a mini oven, so it's economical to run after the initial outlay.

Sausages
Sweet or cheese scones, quick and easy to make
Baked rice pudding
Fruit crumble

Ah good shout, I never think of jacket potatoes!!! :-)

And I always say this when the kids come home from school and boast about school lunch of jacket potatoes, beans and cheese being the best ever!!!

I regularly make a Nando’s fakeaway (sorry - hate that word!). Chicken seasoned in Nando’s rub (£1 from most supermarkets) then potatoes cut into wedges and sprinkled with more peri rub served with salad/spicy microwave rice/corn on the cob. It’s my dcs favourite meal😂

I like roasting peppers, onions and tomatoes, with some herbs, and having them cold like antipasti the next day.

You can apparently (not tried personally) cook eggs like they are hard boiled in the oven too. I keep forgetting to give it a go.

I put in a butternut squash if I have one.

flapjacks.

Baked Potatoes
Cake
Crumble
Sausages
Apples/peaches with raisins and honey in the hollowed-out middle
Flapjack/leftover porridge to make oat bars

If you want to reduce oven usage, think of the next few days of dinners/lunches and snacks, and put them all in together. Reheat in microwave when you want to serve them.

Chickpeas! Throw a tin of chickpeas on a baking tray, spray with oil and season, you can add any spices or garlic etc to flavour if you like. Give them a shake from time to time and roast until crisp, they take on a nutty flavour and make a great snack or salad topper.