In a small bowl stir together the thyme, rosemary, garlic, salt and pepper. Rub the mixture over the pork.
Heat the olive oil in the saucepan. Stir in the ricotta cheese and mozzarella cheese. Simmer for 3 minutes and set aside.
Light one side of your grill and heat to 400F (200C) leaving the other side unlit; place the pork on the lit side and cover; grill for about 10 minutes per side or until browned.
Transfer the pork to the unlit side and cover; grill for about 45 minutes or until internal temperature reads 150F (70C).
Remove from heat and let it sit for about 10 minutes before slicing.
Serve the pork top topped with the cheese sauce.