Tomato and aubergine casserole - can be cooked in stages and can be frozen.
Sliced aubergine either fried or oven baked till it changes texture, put it in layers with a layer or chopped tinned tomatoes (or passata, or a mixture) finish with a tomato layer, top with yoghurt (or yofoo in vegan) then sprinkle on cheese or breadcrumbs at this stage you can freeze it or back for 20mins, if frozen you can bake from frozen for 40mins.
Do you have a steamer? If not get one - much lighter than pans. OK put your potatoes or rice and veg in the steamer, get some foil and make parcels of fish (salmon is good) with some lemon, herbs, pepper, whatever you like and steam the parcels with the veg.
I find mushrooms make a good substitute for meat in things like stews and curries.
get a pan, put rice and smoked haddock in it, season, add a 50/50mix of orange juice and water and bring to the boil, simmer until all the fluid is absorbed.
One starter you could make today and stick in a cupboard for later.
Jam jar filled with sliced mushroom, olives, sliced peppers of various colours capers if you like, fill the jar, and a peeled clove of garlic and pour over olive oil, make sure there are no air bubbles. Serve in a bowl with bread to dip in the oil that will take on a lovely garlic flavour.
This has always gone down really well and I now give jars as gifts.