All the recipes I have found say to use some kind of oil in the pot when cooking the veggies prior to adding the water. I think it may be to prevent sticking. Is there an alternitive to oil? Thank you. Carl.
You really don't need oil, especially if you start with onions. They have a lot of moisture. Browning/caramelization of the vegs will add richness to the final broth. You probably want that, or you'd just throw vegs in a pot of water and boil them. Just add small amounts of water as needed to prevent sticking/burning. But you have to let the liquid cook away while sauteeing to get browning (otherwise you're just steaming). It's a balancing act. Am I making sense?