I stock up when I get paid so could always last a few weeks just topping up with bits -I've had some tight spots in life so am conscious of always having food in so can get by if a bit tight that month.
I always keep in the fresh and tinned dept eggs, teabags, packets of ham, milk, block of cheese, pack of Philly, bread ,yoghurts with a long life, potatoes, salad leaves, cherry tomatoes , 4 or 5 tins of soup, tinned sardines and tuna and anchovies, couple of tins of coconut milk , 3 or 4 tins of fruit , several packets of stir fry sauce, rice, pasta, packets of ainsley Harriott couscous , couple of jars of good quality pasta sauce or passatta , several tins of tomato's, couple of tins of beans, gravy granules
Decent amounts of herbs and spices, soy sauce, Worcester sauce, mustard , and a chutney
Freezer
Loaf of bread
Crusty rolls
Several packs of M&S fishcakes(the cheap ones)
Packet of good fish fingers
Beef mince
Several packets of bacon
3 or 4 ready meals (usually M&S yellow sticker ones)
Packet of chicken breasts (often yellow sticker)
Peas
Green beans
Potato wedges
Roast potatoes
Yorkshire puddings