Preheat oven to 450.
Spread sweet potatoes, onions, potatoes, parsnip, and garlic on a large rimmed baking sheet. Drizzle with 2 tablespoons of olive oil and sprinkle with sea salt. Place on middle rack of preheated oven and bake for approximately 20 to 25 minutes, or until vegetables are tender.
In a medium bowl, combine softened goat cheese, parmesan, dried rosemary, and remaining 2 tablespoons of olive oil.
Stretch dough to fit a 15 inch pizza pan, or into a 15 inch round circle if you are using a heated pizza stone. Parbake dough for 3 to 5 minutes, if desired.
Spread goat cheese mixture evenly over the pizza crust, leaving a one inch border around the edges. Top with roasted veggies and chopped chicken. Sprinkle grated mozzarella evenly over the top of the pizza. Top with fresh rosemary. Bake for 10 to 15 minutes, or until crust is golden and cheese is melted.