Preheat your oven to 425°F (220°C) and line a large baking sheet with parchment paper.
On a floured surface, roll out your pizza dough into a large oval or rectangle, about 1/4 inch thick.
Shape the dough into a triangle with a small rectangle at the bottom to form the tree shape. The triangle should be about 12-14 inches tall and 10-12 inches wide at the base.
Transfer the shaped dough to your parchment-lined baking sheet. If it stretches during transfer, simply reshape it on the baking sheet.
Brush the entire surface with olive oil and sprinkle with Italian seasoning to enhance flavor.
Spread the pesto evenly over the triangle portion of the dough, leaving a 1/2-inch border around the edges to form a crust.
Sprinkle the mozzarella cheese over the pesto, covering most of the “tree” but allowing some green to peek through.
Arrange your colorful toppings (bell peppers, tomatoes, and olives) over the cheese to resemble ornaments on the tree.
Place the red bell pepper star at the top of the tree and position your string cheese or breadstick at the bottom for the trunk.
Finish with a light sprinkle of parmesan cheese over the entire pizza for a “snowy” effect.
Bake for 15-20 minutes until the crust is golden brown and the cheese is bubbling and slightly browned.
Allow to cool for 3-5 minutes before slicing and serving for the best presentation.