Place bell pepper, carrots, onion and head of garlic on baking sheet and sprinkle with olive oil, salt and pepper.
Roast veggies for 30-40 minutes until tender and lightly browned in spots. Watch carefully so they don't burn.
When veggies are tender, place in a large stockpot with remaining ingredients and puree with a stick (immersion) blender. Alternately, you can use a blender to puree ingredients and then transfer to the pot.
Cook together for another 15-20 minutes until nice and bubbly.
While soup is cooking, make the pesto. Toss all pesto ingredients into a food processor and puree.
Serve piping hot with pesto on top. Can also place a dollop of plain greek yogurt (or plain coconut milk yogurt) on top.