Remove the pizza dough from the refrigerator 1 hour before you ready to start. In a large sauté 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 1¾ hour