As oil might go rancid I would err towards Vaseline rather than the spray oil but if you have a little freezer compartment in your fridge you can freeze eggs. The whites freeze fine with out any palaver but the yokes are a little different. Once frozen and defrosted the egg tend to separate so to stop that happening you have to lower the temperature at which they freeze by adding a pinch of salt of a little sugar dissolved in water.
My aunt used to do it years ago when she did a lot of baking, and I see that now we're in lockdown it's making a come back on the interwebs.
The trick is (I've found anyway) is you crack and egg into a cup gently stir to mix yoke with white, add a tiny pinch of salt, the whole time being very careful not to add any air because the air bubbles will get freezer burn, then pour into a silicone baking case and place in the freezer til hard then pop out of case and into a freezer bag.
I'll see Monkey his butter and raise you ghee. Ghee is brilliant stuff, stupidly expensive to buy but very easy to make (once you get the hang of it), because you have removed the milk solids from your butter it is much less likely to go off, it will last months longer than actual butter, and has a much higher smoking point when used for frying, in a lot of ways it's much better to use for frying than oil. It also has better consistency than oil and better health benefits over butter and other cooking oils.
I always keep a healthy stash of Al'Fez Humous, it's much tastier than the stuff you get in the likes of Tescos chilled section and has a really long shelf life because it comes in a sealed jar.
Lidls do packets of cooked potatoes that keep for a really long time too. Boxes of potato gratin for example in the chilled section, they last about a month or so, possibly longer.
Miso paste is brilliant stuff and amazingly versatile, it can be mixed with butter, used as a broth base, or coated on meat and fish before cooking. Miso and tamari are a reach for staple in my kitchen. Add tamari to scrambled egg instead of milk for something yummy and different.
Not to everyones taste but biltong is great stuff to take boating, it is quite expensive but lasts on the shelf for months (years) and is really tasty, salty so you can't eat too much in one go but sooo yummy. On a serious note I keep biltong in my emergency rations pack because it's light, easily carried and does what you need it to do, it's not a meal but it is handy for what it is.
Never leave home with out at least a hundred tubes of tartex pate cos that stuff never goes off.
Another staple is Engevita yeast flakes which are great on a baked potato or added to a pasta sauce to make it go further.
Chia seeds are also a good one to keep on hand as they can make a nice pudding or can substitute for an egg if baking.
Banana blossom, jack fruit and tofu also have long shelf lives and are good to keep on hand; I know they're used a lot as a meat substitute but I like them for what they are in their own right and then I'm not disappointed expecting then to be something they're not. If nothing else they are handy for a worst case scenario.
Couscous is always handy because it stores well and needs no actual cooking, add a bit of bouillon or miso or even lemon/lime juice to the hot water you use to soak it and that makes it much more interesting.
Of course those are the sort of things I like and keep on hand they might be of no use at all if they're not your cuppa tea.