oven cooked fish - usually cod or salmon - just wrap in foil with lemon wedges - with salad. Sometimes do oven chips or home made wedges, sometimes rice with peas and sweetcorn, sometimes just a slice of decent bread
Lasagne can be simpler if you double up when you do bolognaise and freeze, take it out in the am then by tea time its ready to layer up, make a bechamel and sprinkle with grated cheese and shove in the oven with garlic bread
We like a beef stew which takes a bit of time however if you combine with baked potatoes it purely is a shove it in the oven for 2 hrs and pots for 1 1/4hrs. It helps I have an always on oven so energy less of a consideration.
Also roasted med veg with rice or cous cous and this can be with fish or meat to taste - just add some herbs and cook sep in the oven to the veg
Another thing I often do is prep fr the next day so for e.g. if having baked potatoes i do extras that can be skinned and used for mash on a shep pie or fish pie with the skins becoming loaded skins if you like that sort of thing.
We often have roasted ham but then with left overs do a basic potato and ham stew - liturally precooked meat, stock, carrots, onions (celery if u like it) and potato (waxy and floury if you can a floury thickens it) and cornflour to thicken the gravy a bit if you prefer. All goes in the pot and when the potatoes are soft its done. Great for after a day outside or day out to be ready quick and warming, served with bread if you want