Making Italian Sausage Gnocchi Skillet is a straightforward process. Follow these simple steps for the best results:

1. Cook Sausage: In a large skillet over medium heat, add the Italian sausage. Cook until browned, breaking it up into smaller pieces as it cooks. This should take about 5-7 minutes.
2. Add Onion and Garlic: Once the sausage is browned, add the diced onion and minced garlic. Sauté for an additional 3-4 minutes until the onion becomes translucent.
3. Add Tomatoes and Sauce: Pour in the diced tomatoes (with juice) and tomato sauce. Stir to combine.
4. Season: Sprinkle the Italian seasoning and red pepper flakes (if using) over the mixture. Season with salt and pepper to taste.
5. Add Gnocchi: Gently stir in the gnocchi, ensuring they are evenly coated with the sauce.
6. Simmer: Cover the skillet and let it simmer for about 5-7 minutes. This allows the gnocchi to cook through and absorb the flavors.
7. Add Spinach: If desired, add fresh spinach to the skillet during the last 2 minutes of cooking. Stir until wilted.
8. Top with Cheese: Remove the skillet from heat and sprinkle shredded mozzarella cheese over the top. Cover the skillet for 2-3 minutes to let the cheese melt.
9. Garnish and Serve: Once the cheese is melted, garnish with fresh basil, if desired. Your Italian Sausage Gnocchi Skillet is now ready to be served!