Preheat oven to 180C Fan and place a baking tray onto the middle shelf.
Rub each sweet potato with a teaspoon of the olive oil and some salt. Pierce the skin with a sharp knife in several places
Place the potatoes directly onto the top shelf, above the tray. The tray will catch any leaks.
In a small bowl mix together the pesto and mozzarella.
Bake the potatoes for 1 hour or until soft then remove from the oven. Cut a cross in the top of the potatoes and break them open. Fluff up the inside with a fork and fill with the pesto mixture.
Serve immediately with a green salad.
Notes
*I use a reduced fat "lighter" Mozzarella cheese ball in my recipe and calculation of the nutrition facts.