"I have found oven roasting vegetables moe flavorful and easier to cook. I use extra virgin olive oil and go no higher than 375 degrees to prevent smoking. Do you have an opinion about this practice? My concern is about changing the molecular structure of the oil from over heating and getting the wrong balance of omegas."
You could simply supplement with flax seed oil to ensure that you always get the appropriate balance of omega oils. Flax seed oil does not normally contain any omega oils, but it instead contains the precursor compounds that a body easily uses to manufacture its own omega-3 as needed. This is why we (and Dr. Johanna Budwig) recommend only flax oil for omega supplementation, because it allows a body to self-regulate the omega balance as is needed at any given time. Most of the other omega supplements tend to overload a body with omega-3, which harmfully upsets the balance. Then as they go rancid, they harmfully shift into flooding the body with inflammatory omega-6. For example, pristine fish oil is bad for having too much omega-3, and oil which has become rotten is even worse. Just use cold pressed and properly packaged flax oil. Your body will automatically take care of the rest. Your vegetable cooking is probably fine, and you probably do not need to change anything. However, it is worth mentioning that steaming instead of roasting would preserve more of the nutrients.