Mince the garlic clove in a food processor until fine. Add arugula leaves, walnuts, and a bit of the olive oil and process, continuing to drizzle in olive oil until a pesto texture is achieved. Add salt and pepper to taste and set aside.
Spread or roll pizza dough to the desired thickness and set aside to rest a few minutes.
Slice off stems of figs and cut into quarters. Brush lightly with olive oil and grill over medium high heat until grill marks appear, about 3 minutes. Remove to a plate and set aside.
Brush pizza dough lightly with olive oil and place oiled side down on the grill. Cook over medium low heat until first side is lightly browned, about5-8 minutes, checking every couple of minutes for bubbles that need to be popped in the crust.
Flip crust over to the other side, and spread crust with most of the arugula pesto. Layer with prosciutto slices and place grilled figs on top. Sprinkle Gorgonzola crumbles over the top and dot with remaining arugula pesto, and continue to grill until the crust is fully cooked and the cheese has melted, about 5-10 minutes. (If the crust is becoming too dark on the bottom but isn't cooked through, move the pizza to a side of the grill that is turned off and allow it to cook from indirect heat from the remaining side that is turned on.)
When pizza is cooked through and cheese has melted, remove from the grill and slice and serve.