Preheat the oven to 400 degrees F.
Place the potatoes and squash in a large bowl and toss with olive oil, rosemary, thyme, garlic, and salt and pepper to coat well. Transfer vegetables, with your hands, to a large baking sheet and spread into a single layer, keeping any leftover oil from the bowl. Roast the vegetables until tender, turning every 10 minutes with a long-handled spoon, about 45 minutes to 1 hour.
Remove from the oven and add as much leftover oil to the vegetables as desired, and season to taste. Serve immediately.
Yield: 4 to 6 servings