Preheat the oven to 400ºF. Line baking sheets with parchment paper. Spread out the peeled, chopped potatoes and coat with olive oil, salt, and pepper
In a medium skillet, warm the remaining 2 tablespoons oil over medium heat. Add the chopped onion, parsnips, and thyme, 1 teaspoon salt, pepper, the basil, dill, onion powder. Sauté for 5 minutes, or until the onion and is fragrant and translucent. Add the garlic and cook for an additional 3 minutes. Transfer it to the medium pot and add sweet potatoes and veggie broth.
Cook until vegetables are tender. Adjust seasonings to taste.
Serve the soup in bowls, topped with fresh thyme, and an optional drizzle of olive oil. Serve hot/warm. Store in an airtight glass container in the refrigerator for up to 1 week.