Heat a small (6- or 7-inch) nonstick skillet over medium heat until a drop of water sizzles and evaporates on contact, about 2-3 minutes. Sprinkle the ½ cup parm around the border of the skillet to form a ring, leaving 2-3 inches of the center of the pan exposed. Cook until the parm begins to brown and crisp, 2 minutes. Spoon in 2-3 tablespoons of the pesto and heat until bubbly, 30 seconds. Crack the egg on top of the pesto, let cook 1 minute, then cover and let cook until the white is opaque, 1-2 minutes. Uncover and use a silicone spatula to slide the whole thing onto a plate, Season with salt and pepper and garnish with basil leaves.