Preheat the oven to 425 degrees F. Put the carrots into a large pot and the beets into another, and add enough water to cover them (you can also steam them in the microwave). Season with salt and bring to a boil. Cook for 15 to 20 minutes until just tender, then drain and place in separate bowls. Peel the beets, and cut any larger carrots and beets in half or into quarters. Smaller ones can stay whole.
Now add the flavorings while the vegetables are still hot. Place the carrots and beets in an oven proof dish and toss with half the smashed garlic and some olive oil, then lightly season. Add the thyme leaves rosemary balsamic vinegar salt and pepper and toss again. Place in the middle of the preheated oven and roast for around 1/2 hour or until golden.