Preheat oven to 220°C/200°C fan-forced.
Place spinach in a large fine sieve. Using back of a spoon, press spinach to remove excess liquid. Discard liquid. Place spinach in a large bowl. Add ricotta and season with pepper. Using a fork, mix well to combine.
Place one-eighth of the spinach mixture along 1 side of each ham slice. Roll up to enclose filling. Place ham rolls in a single layer, in a greased 22 x 39cm (4cm deep) oval baking dish. Pour sauce over ham rolls and scatter with cheese
Bake for 20 minutes or until filling is heated through. Turn on oven grill to medium-high. Grill for 4 minutes or until cheese is golden. Scatter over basil, season with pepper, then serve.
Servings 4