Can I make mushroom soup in the slow cooker? How?

[IHeartKingThistle]

I'd like to use onions and leeks in it, just keep finding floppy American recipes!

Ha! Not floppy, gloopy!

I think it would work, you'd still need to sweat down onions and garlic and thyme and then brown mushrooms and drive off as much moisture as possible. Then I'd stick it all in slow-cooker with stock (chicken or veg) and put it on low for as long as you need. It would need reducing, so maybe an hour before you need it, on high with lid off. Blend if you want it sooth and finish with creme fraiche and seasoning stirred in. Bit of lemon juice right at the end if it needs a bit of lift. HTH!

I would class mushroom soup as something you could do in the slow cooker but shouldn't.

There's a Facebook group called slow cooked wonders where you can find recipes for almost anything in the slow cooker.