Remove the pizza dough from the refrigerator 1 hour before you ready to start.
In a large saute pan over medium low heat add 2 tbsp of olive oil.
Add onions and slowly caramelize until brown and creamy about 20 minutes.
Set aside to cool.
Preheat oven to 500 degrees.
Heat the grill over medium-high heat and wipe down with oiled paper towels to create a non-stick surface.
On a floured surface, roll out each of the pizza dough into an elongated shape, about 12 by 8-inches and about a 1/2-inch thick.
Brush with olive oil and grill on both sides until warmed through and grill marked, about 4 minutes per side.
Transfer to a baking sheet.
In a medium bowl, mix together the mascarpone and blue cheese.
Smear the cheese mixture over each of the grill pizza crusts.
Place in oven for 2 to 3 minutes until the cheese melts.
Remove from oven and transfer to cutting board or platter.
Top with caramelized onions, toasted walnuts and fresh grapes.
Season with a few turns of freshly ground black pepper, drizzle with some more extra-virgin olive oil and top with fresh parsley.
Ready in 1 hour.