Do I need to brown the onions in a pan first?

[hugoagogo]

I want to make soup, without stinking the kitchen out, can i do it all in the slow cooker?

It won't taste as nice
The point of browning is to kick off the maillard reaction and caremalise the sugars in the onions

This is why those soup makers can't make proper soup. You have to cook certain ingredients in certain ways.

Onions will brown OK with a lid on the pan to contain the aroma

I batch caramelise onions (the bags of chopped frozen onions are very handy for this) and freeze in single onion portions - very handy to chuck straight into soup and other dishes. I originally came across this idea in Miss South's slow cooked so it can be done in the slow cooker but takes a while.

You can do it straight in the slow cooker. It won't be quite as nice but will be perfectly edible. If skipping the browning, put them at the bottom.

I love the smell of fried onions!

I like the smell too, for a while, but we don't have an extractor and it tends to linger.

If you put them straight in, or a slow cooker, it’s a bit raw onion-y tasting.

I was thinking of cooking the onions in a just a bit of oil first so they are softened. It's worth a try I think.

That’s exactly what you need to do.

I love the smell of brown onion.