Great question — answering as the UphillTech team:
The fat would have emulsified with the water released by the vegetables (a bit like how mayonnaise works), that's why you can't see any free fat in there. If you want to be able to see the fat you can either add more (at any stage of cooking), or cook out enough of the liquid that the emulsion breaks and the fat separates again. It would end up very mushy probably. Yes, it's up to you how much more fat, I don't think there are any hard rules here. I'm not entirely sure what you mean by this question so I'll try and give you some info that I think is relevant. In general harder vegetables take longer to cook than softer ones, and larger pieces take longer than smaller ones. You can add the...
Full answer by user13716: https://cooking.stackexchange.com/a/128411 (CC BY-SA 4.0).
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