No onions could I use a leek instead?

[TedOnTheBed]

Make spaghetti bolognese for dinner tonight, just about to start the sauce off to slow cook on the hob and I have no onions. Could I substitute them with leek? 3 dc have covid so I can’t nip out to get any as they are to young to leave alone and obviously in isolation. Uber eats etc aren’t available in the small village I live in do not an option.
Thanks

Short answer. Yes.

Yes, very finely chopped - you might like it! Or celery if you've got any kicking around.

It catches must easier than onion though so go slow and steady!

Definitely...and chuck in a bit extra garlic to balance the flavour.

Thank you, have plenty of garlic so will add extra and a couple of stalks of celery.
Thank you

Yes. I would actually slice them a bit thicker and cook them a little less as they are less strong then onion. Unless you want them to kind of disappear of course. They’ll work well either way.

Onions are added to tomato based sauces for sweetness and to balance the tartness of the tomatoes. So it’s probably better to substitute with a finely chopped carrot if you have it, or just add sugar to taste