In a food processor add all the ingredients for the pesto and blitz to the desired consistency of your pesto. I like mine with a bit of a bite!
Slice your Italian bread through the middle and generously spread the pesto on both sides.
Layer on your spinach leaves and then sliced tomato. Season the tomatoes with salt and black pepper and then top with the sliced buffalo mozzarella.
Close your sandwich and then slice at an angle and that's it!