Preheat oven to 400 degrees.
Thinly slice onions and add to small pan, cook over medium heat for 15-20 minutes, stirring occasionally, until onions caramelize.
While onions cook, add all pesto ingredients to bowl of food processor and process 12-15 seconds.
Add flatbread to baking sheet and bake 5-6 minutes or until flatbread is crispy without being burned.
Remove flatbread from oven, add pesto, followed by shredded mozzarella, grated Parmesan, caramelized onions, goat cheese and roasted pumpkin seeds, bake additional 5 minutes or until cheeses have melted. Enjoy!