2 weeks?
Some bottled water for drinking, and make sure the rain butt is full for washing/toilet needs.
Dried and tinned milk for some extra, and 1 carton frozen.
Frozen meat (a mix of things - chicken, mince, salmon, prawns, lamb chops, sausages etc, but enough for at least 9 meals) and frozen dinners (spag bol etc)
Jars of sauces that we will eat (curries, pasta sauces, etc)
Rice, pasta, couscous - and my emergency packet of dried mashed potato - I always have a basket of regular potatoes anyway - a mix of roosters, baby potatoes and sweet potatoes, all of which are relatively long life
Tins of tuna, sweetcorn, tomatoes, coconut milk, chickpeas, spaghetti hoops, baked beans
Cartons of fruit juice
Packets of wraps - also relatively long life, and some part baked bread rolls
Biscuits, crisps, popcorn kernels/microwave popcorn to make
Squash, wine, beer, sparkling water
Eggs - at least 2 dozen if I thought I was likely to be stuck at home
Longer life veg - onions, garlic, carrots, butternut squash, cooking apples etc
Longer life fresh meats - bacon, chorizo etc.
Cured/smoked stuff - salamis, smoked salmon, etc
Hard cheese - cheddar, parmesan, smoked cheese etc
Baking ingredients - flour, sugar, butter, etc. Can make bread, pancakes, biscuits, cakes, pies - all both to eat and add variety, extend life of existing stocks, and also to pass the time if in a lockdown situation (so might make a proper cake and spend time decorating it beautifully, not just a basic loaf-cake to eat).
Emergency supplies - cleaning, first aid, antibac bottles, toilet rolls (lots), kitchen towel, bin bags....
Heating and lighting - candles, matches, firelighters, logs etc.
Batteries for torches, make sure the windup radio is working etc
Cards, board games, …..books