Preheat oven to 375 degrees. Fill a slice of ham with a little ground beef. Roll into a ball. Repeat until you run out of ham slices.
Pour a little tomato sauce into a casserole dish to coat the bottom. Place stuffed rolls in a row until dish is full.
Top with more tomato sauce. Then cover with ricotta cheese. Pour another layer of tomato sauce over the ricotta, then sprinkle with mozzarella cheese. Cover dish with foil.
Bake approximately 1 hour, until meat is cooked through and sauce is bubbling.