In a large, deep skillet with a lid, heat olive oil over medium heat. Add the Italian sausage and break it up with a meat masher or wooden spoon until just browned.
Add the onion and garlic and stir occasionally for 2-3 minutes.
Add the tomatoes, oregano, parsley, basil, fennel, chili flakes, salt and pepper. Stir while breaking up the tomatoes with your spatula or spoon.
Once the tomatoes are broken up and the seasonings are combined, stir in the orzo until fully coated.
Add the broth and stir until combined once again. Bring to a boil over high heat, cover, then simmer on low for about 15 minutes, stirring every 5 minutes to ensure the orzo doesn’t stick to the bottom.
Once most of the liquid has been absorbed, stir in the kale and top with mozzarella cheese. Turn the heat off and cover for 2-3 minutes until the cheese has melted.
Garnish with fresh basil or parsley and serve!
