Dust the surface of a pizza peel with semolina flour and place the dough you are using. Lightly brush a one inch border of extra virgin olive oil around the pizza. Spread the sage pesto around the rest of the pizza and then evenly distribute the caramelized squash, the goat cheese, the pancetta, and the leek atop the sage pesto. Bake in the oven for 10 minutes until the cheese has slightly browned. Remove from the oven to a cutting board and add fresh cracked pepper, parmagiano reggiano, and additional nutmeg. Slice and serve immediately.
For the sage pesto:Combine the walnuts, sage, parsley, salt, and nutmeg in the bowl of a food processor and pulse 10 to 15 times to break up the walnuts and herbs somewhat. With the processor running, slowly pour in the olive oil. Taste and add additional salt if needed.
For the caramelized butternut squash:Preheat the oven to 400 degrees. Place the diced squash on a baking sheet lined with parchment paper. Drizzle with the olive oil and balsamic vinegar and add salt and pepper to taste. Bake for 30 minutes until the squash is tender, mixing once after 15 minutes. Let cool.