Preheat the oven to 400°F/200°C.
Peel and chop carrots and onion.
Remove outer leaves from Brussels sprouts and cut into halves.
Cut potato and squash into slices.
Place carrots, onion, Brussels sprouts, potato, and squash in one even layer on a baking sheet. Do not overlap or vegetables will steam instead of roasting.
Sprinkle vegetables with oregano, rosemary, thyme, and basil. Add salt and pepper to taste. Add olive oil and toss well, evenly coating all vegetables with seasonings and olive oil.
Place baking sheet on the middle oven rack and bake for 20 minutes. Pull the baking sheet out, flip vegetables, and continue baking until ready, about 10 more minutes.
Remove from oven, put on dinner plate, and serve.