Different cooking methods produce different results, it’s not just about onions. But the maillard reaction comes from frying them, theres also a textural element to the difference. Using fat promotes allows browing and even caramelization.

Try using less fat to fry them instead of 0 fat. If you’re talking about deep frying, then try the microwave method from americas test kitchen.

(Im not a 100% sure I’m right but i’m fairly confident)

I’m not sure, but I know that when a family member had to do a low FODMAP diet, they couldn’t eat things with onions in them. But onion infused oil was fine because the sugars in the onion were water soluble, but not fat soluble so the oil didn’t contain the component they were avoiding. https://www.monashfodmap.com/blog/all-about-onion-garlic-and-infused-oils-on-the-low-fodmap-diet/

Not sure it’s related but it’s the first thing I thought of.

@SubArcticTundra Because the flavor goes into the water! That’s why soup broth tastes good. Try chopping up half an onion, boiling for 10 minutes in a pot with enough water to cover them, then taste the water.

Steam / water doesn’t allow the temperature to get high enough.

I’ve never heard of sautéing them in water I just throw them straight in the pan

“saute on water”?

How’s that different than steaming or boiling

I had a whole post typed up but my app crashed. Lol.

America’s Test Kitchen has a video on this and it’s pretty interesting: https://youtube.com/watch?v=rzL07v6w8AA

At 2:12 she caramelizes onions in a pan. I like ATK because they explain the science behind it.

edit: I’d suggest watching the whole video because it’s pretty dang interesting. Hope this helps! :⁠-⁠)