This is more of a method than a detailed recipe. Use whatever you have in the vegetable drawer or whatever looks good at the store or market. Try to cook veggies of similar hardness together (like carrots and potatoes OR zucchini and tomatoes) or you can adjust size of pieces or just take some of the vegetables out of the oven sooner than the others. Once you start roasting, you’ll get a feel for how long different veggies take and what size you prefer them. For example – do you want them bite size or larger pieces that require cutting?
Line roasting sheet/cookie sheet with parchment if you like. Makes for easy clean up. I use 12 X 17 sheets pans – often filling up two of these with vegetables so I have leftovers or can feed a crowd.
Cut vegetable (s) of choice into pieces and spread on your cookie/roasting sheet. I usually put each vegetable into their own sections so if they cook faster, it is easier to remove them and let the others finish cooking.
Now add some olive oil – about 2 tablespoons per sheet pan. I just pour but measuring is a good method so you can get an idea of how much you prefer to use when you roast. Then I add salt and pepper – probably about a ½ to 1 teaspoon of each per sheet of vegetables. Then mix it all around right on the parchment. Also add other spices if you like – think about what else you are serving and choose spices to complement your protein and the vegetable. But just olive oil and salt and pepper is magical. When the vegetables are done, they will be caramelized – even almost burnt. When I take them out, I like to squeeze fresh lemon juice on them – it is an excellent finishing touch.
I roast my vegetables at 375 degrees convect or 400 degrees conventional. I usually check them and toss them about at about 10 minutes, then cook additionally at 5 minute intervals. If you roast asparagus – (see this recipe), it cooks very quickly if the spears are thin – more like 7 minutes total.