Combine all prepared vegetables, pear slices, and pecans in a bowl. Add olive oil and toss liberally with the vegetables. Add the chopped sage, sea salt, and black pepper, and mix again.
Place the mixture in a deep roasting pan and roast in a preheated oven at 425˚F.
After 20 minutes, give the pan a shake to prevent vegetables from sticking to the bottom and produce a more even roast.
Continue roasting for an additional to 20 to 30 minutes. The vegetables should be nicely roasted with dark caramel colouring and the vegetables should be easily pierced with a fork.