There are a couple of tricks to get the desired end product by roasting. First, precook the vegetables by starting them in the steamer. This starts the cooking process which reduces the roasting time and it also helps to maintain the moisture content the dry heat will rob. Vegetables are precooked when the tip of the knife can just penetrate the first quarter inch. Next, to further retain the moisture of the vegetables use a Dutch oven or covered pot. If that is not convenient, at least cover them with a sheet of aluminum foil with a few holes poked in it. Finally, roasting is done at high temperatures – 450 degrees Fahrenheit. The high temperatures brings out the natural sugars and caramelizes them on the surface of the vegetables for a wonderful flavor.