Make the pesto: place the toasted pine nuts in a bowl (or mortar) and crush with a wooden spoon (or pestle) to make a chunky paste. Add in the garlic and a pinch of salt and combine. Mix in the basil and Parmesan. Stir in the olive oil and season with pepper.
Put a pizza stone onto the floor of the oven and preheat the oven to 425 degrees F.
Put the dough onto a floured surface and knead and stretch the dough to about an 8-inch diameter. Dust a wooden pizza paddle with cornmeal and carefully transfer the dough. Spread the pesto over the dough, leaving 1-inch around the edge to form a crust. Top with the onion and tomato slices and season with salt and pepper. Scatter the olives all over the pizza and top with the fresh mozzarella. Slide the pizza onto the stone and bake until the cheese is melted and the crust is golden, about 8 to 10 minutes.