I cook the veggies on a low heat in a shallow pool of water until they're transluscent

by cooking them in water you're restricting the cooking temperature to 212F which is going to prevent significant maillard reaction/browning from occurring, and you're robbing yourself of savory flavor

at the very least fry the onions in oil, then the garlic for like a minute, before adding the water

P.s. if you dice an onion and toss it in oil and put it in the oven for like 2 hours at 225F you get caramelized onion (i mean check on it and stir every 30 minutes idk how your oven be)