Roasted vegetables are the umami of the plant world. Their depth of flavor is without compare. The browning (maillard effect) is how you develop the umami, caramelizing the natural sugars in the vegetables. Use roasted vegetables as a side dish, base for soup or dip, served with greens and a balsamic vinaigrette, or as the star of the recipe sitting atop pasta, rice, cous cous, quinoa, or farro.
The vegetables above are an example of the assortment I would use for a roasted vegetable broth. Any veg will do, except for the brassica family, which includes broccoli, cauliflower, collards, kale, and cabbage. They would give an off-taste to your broth. Root vegetables and celery are the traditional choices. Leaving the skins on onions and garlic, only removing the root end, adds even more color to the broth.
Roasting cauliflower is very popular right now. Adding Moroccan or Lebanese spices really adds to the exotic flavor. Broccoli can also be treated in a similar fashion.
Butternut squash can be roasted whole for soups and pies. I don’t even seed them beforehand. Just place them cut side down on parchment paper, no oil required. This is my favorite for “pumpkin” pie. After I scrape out the flesh, I puree the flesh in the food processor and drain for 6 to 12 hours to remove any extra liquid.
Larger pumpkins and winter squash can be cut into large, manageable pieces to roast. Above is a quartered Blue Hubbard squash. Since they won’t have a singular side to face down on the pan, lightly coat the exposed sides with oil.
Red bell peppers need no oil. I prefer roasting in the oven rather than the gas flame method because I like the pepper cooked through. No need for a paper bag to steam off the skin. Just let it cool to room temperature and it should separate quite easily.
Asparagus is a different taste altogether when it’s roasted. My tips always frizzle, but so what. I could have undercooked them to make a prettier picture, but we’re making it real here and my roasted asparagus always looks like this whether they are slender stalks like above or thick, meatier spears.
Garlic requires a little extra attention. It also doesn’t take as long as all of the others above, so keep your eyes on it. Your nose will also know when it’s done. Cutting off the tips allows the oil to penetrate each clove. Some garlic varieties have a cauliflower shape, so I cut the top off and then each outer/shorter tip individually. A quick squeeze pops them right out of their skins.
Directions for roasting are probably the most broad for temperature range. The idea is to pump up the heat, but not too much to cause the vegetables to dry out. Leaving space between the vegetable pieces will allow the heat to surround each piece and prevent steaming and facilitate browning. Lining a baking sheet with parchment will help with clean-up.
I’ll roast vegetables usually at 425 degrees. Check every 15 to assess the cooking process, turning the vegetables (except winter squash) each time. If some are cooking faster, just remove them continue cooking the more dense ones until done. Cook until fork tender and browned. Cooking times will vary, dependent upon the size you’ve cut your vegetables and how much moisture they naturally contain. So, as in many things in life, it’s all relative.