When you toss vegetables lightly in olive oil, and spread them out on a sheet pan, and put them in a hot oven something magical happens: caramelization. Roasted vegetables are one of my favorite things, especially cauliflower, kale, and rapini. I take them out of the oven, drizzle them with a little lemon, and often before the rest of the meal is ready Dave and I will devour a large bowl of vegetables. They make a delicious snack or appetizer.
Roasting vegetables is one of the easiest methods to cook them, but I cannot tell you how many times I see people doing it wrong. From newbie cooks at work, who are unknowingly revealing just how much they have to learn, to friends and family who have simply not been told the important rule, people mess it up. The biggest secret to well roasted vegetables? Spread them out.
Overcrowd vegetables on a sheet pan will release their moisture and steam before they will caramelize. You might eventually get enough color, but the vegetables will likely be overcooked before they develop the color professional cooks seek out. Caramelization equals flavor. Steamed vegetables are delicious in their own when, but when you choose to roast vegetables, you are seeking a different flavor. Think of grilled chicken versus poached chicken, which would you rather have? Therefore, to roast vegetables properly, you often need to dirty another sheet pan or two.
Hot ovens are also the way to go. I've noticed a lot of home cooks are afraid of heat. Baking a cake or cookies? Roasting a bird? Toasting nuts? Go ahead and drop your oven temperature down to 325 or 350. Roasting vegetables? Learn to embrace 450, or 500. Our ovens at work rarely dropped below 500 degrees F. Yes, you'll have to watch what is in the oven a bit more closely, but it will help you obtain the sexy caramelization we want without turning your vegetables into mush. The side of the vegetable that is on the sheet pan will get more color, so don't be afraid to mix them up a bit and turn them over while they are cooking.
Roasted Cauliflower Soup (makes 2 qts)
Two heads of cauliflower, cut into larger pieces
one onion, roughly sliced
garlic to taste, 6-10 cloves ought to be good, peeled and thinly sliced
dried small chilis such as arbol (optional, to taste)
juice of one lemon, or 1 T champagne vinegar
Preheat oven to 500 degrees F while preparing vegetables. The soup is going to be pureed, so it is not important that they look pretty, but you want them to be roughly close in size so they cook at the same speed. When oven is preheated, begin roasting the cauliflower. Spread it out onto at least two sheet pans. Preheat soup pot to a medium low heat. Add about a T of olive oil. Add onions and garlic, and a little salt. Sweat the onions and garlic slowly until translucent. The cauliflower will take about fifteen minutes, but keep an eye on it. You want dark color, but you don't want it burning. If you choose to add chilies, remove the stems and throw them on the sheet pan in the last few minutes to toast them. When the cauliflower has deep, dark brown and golden color, pull it out of the oven and add it to the soup pot. Cover all ingredients with water. It should take a little less than two quarts of water. It is better to use less water to start, and thin it out later if need be. Bring the water to a simmer and cook for about fifteen minutes. Puree the soup with an immersion blender.. If you have to use a real blender, do it in batches, and be sure to start the blender on low before turning it up so that hot soup does not shoot out the top. (I made that mistake once with carrot soup at work, ouch!.) When the soup is pureed, you should add a little acid. I recommend lemon juice, or a little vinegar. Adjust the seasoning. I garnished my soup with truffle oil, which is what we used at Fratelli. Yum!