Heat oven to 475°F. In large bowl, toss sweet potatoes, peeled and cut into 1/2-inch strips, with olive oil, Italian parsley, thyme, and garlic. Sprinkle generously with salt and pepper.
Spread sweet potatoes in single layer on large baking sheet coated with cooking spray. Bake until tender and golden-brown, turning occasionally, 20 to 25 minutes.