For a really easy meal, mince and potatoes: a much under-rated British classic, if properly done.
Cop an onion and fry it in oil until it's soft.
Add about 500g of mince, fry until mostly cooked.
Sprinkle in a spoon of flour and stir it about, then add about half a mug of water, salt, pepper, 1-2 Oxo or other stock cubes, a tablespoon of Worcestershire sauce and a teaspoon of mixed herbs. Just let it simmer until it thickens up - I give mine quite a long time.
As it simmers, prep and boil the spuds, Serve them with salt, pepper and butter.
A basic beef stew is also a good one.
One of my student staples was cooked pasta, still hot, mixed with a tin of condensed mushroom soup, a few actual mushrooms sliced quite small, and salt, pepper and mixed herbs, all stirred together in an oven-proof dish, flattened out and covered in grated cheese. Bake it for about 20 mins and serve with a green veg,
You can jazz it up by adding friend onions, or making your own sauce.