Place a pizza stone on the grate. Preheat the grill, setting
the burners to high.
On a floured work surface, divide the dough into 4 pieces. Roll one piece of dough at a time to a circle about 10 inches (25 cm) in diameter. Place the rolled-out dough on a sheet of parchment paper.
Top each pizza with 1/4 cup of the crème fraîche and one-quarter of the onion. Season well with pepper. Place 1 pizza at a time on the pizza stone, close the lid and cook for 8 to 10 minutes, or until the crust is golden brown.
In a bowl, combine the green onions and herbs. As they come off of the grill, garnish each pizza with the herb mix and top with seafood. Drizzle with olive oil.