Before you go "no I literally can't do that" yes you literally can and I'm gonna tell you how. There will be people in the comments who say no that's not a stock no that's not the way no not like that but they're wrong. You're not a Michelin Star Chef you're just trying to make something cozy with shit you normally throw away and anyone trying to stop you is reactionary. Just make it and enjoy it. I'm not expert so just use this as a guide to get you started, you do it your way and it'll be perfect just the way you like it.
Anyway here's what you need to do. Starting RIGHT NOW get a freezer bag or container ready and every time you're about to throw away some scraps, instead, put it in your container and put it in the freezer. What kind of scraps? Anything I don't care. Leek tops or potato skins or slightly off spinach or the part of the onion you didn't feel like cutting properly or jalapeno stems or apple cores or that leftover bit of fresh thyme that you forgot about after you didn't need the whole thing or some be peppers that you are like are these still good or just whatever. Shit can be raw or cooked or seasoned or sauced or whatever. It's not rocket science just put your scraps in the freezer it's fine they'll get all freezer burned and nasty but who cares you were gonna throw em away anyway.
Doesn't have to be veggies either can be meat, cw here for folks who don't wanna know but otherwise here's more ideas
CW for meat ideas
Bones or fat or shells or cooked or raw or trimmings or giblets or whatever look if you're gonna eat a dead animal don't you fucking dare throw any of it away without getting the most out of it okay?
Again it doesn't have to be pretty it doesn't have to be good it just has to be not moldy or totally rotten.
Okay do this for 6 months and then come back.
Hello from the past I guess it's been 6 months hopefully you got a bag or three full of random trimmings.
Put them in the biggest pot you got. If you're doing meat stuff put that in first without the veggies.
Cover the stuff with water.
Salt the shit outta it. Other seasonings too if you want I don't care it's your stock do whatever.
Stove. Cover it. Make hot. Simmer. Do like an hour before adding veggies if you're doing meat otherwise do the veggies for like 2 ish hours or something. It's not an exact science once it's been simmering for a while taste it. If it tastes like water add salt. Do this untill it stops tasting like water. Then keep tasting and looking at the veg once they're looking all sad and gross and it tastes really delicious take it off the heat. Grab tongs or a spoon or something. Pull out all the stuff you put in It's done congrats you made stock.
You can just eat it if you want just like this. Maybe with some rice or noodles. Or you can strain it if you're feeling fancy. You can put it into ice cube trays and freeze it and put the cubes in a container and later when you need some just pull some out.
It's so easy and it costs you basically nothing but the energy to cook and the salt. Otherwise you were gonna throw all that delicious flavor and nutrients out.
Don't waste your food folks use all of it you paid for it someone picked it.
You can do this don't let anyone tell you not to they're wrong and dumb go make delicious stock just for you you'll be happier and healthier for it. I'm gonna go eat some of mine right now as a base for some tomato soup.