Right, you need to buy things like pesto sauce or curry paste which last for ages in the fridge.
Also things like 'Straight to Wok' noodles which come in one-person size packs and will take literally 5 minutes to stir-fry with some strips of chicken breast, (or pork or beef steak) plus a couple of bits of veg.
New pots are really quick to cook and last for ages; you could have these with baked salmon and frozen peas. Or a grilled chop.
Plain pizza base, add your own toppings.
Ready-roasted chicken portion with salad (in fact substantial salads are good full stop)