Cook ground round, onion, and garlic in a large skillet over medium heat until ground beef crumbles and is no longer pink; drain well. Return to skillet; stir in 1/2 cup spaghetti sauce and Italian seasoning.
Unroll French loaf; roll into a 16-inch square. Cut into 4 squares; spoon 1/2 cup ground round mixture into center of each square. Top each with a slice of mozzarella cheese. Fold over to form a triangle, pressing edges to seal. Place on a lightly greased baking sheet.
Bake at 400° for 12 to 15 minutes or until browned. Serve with remaining spaghetti sauce.
Prep: 15 min., Bake: 15 min
NOTE: For testing purposes only, we used Ragu Mushroom & Green Pepper Chunky Garden style pasta sauce for spagetti sauce.