Heat olive oil in a large skillet over medium heat. Add sausage and onion. Cook, breaking up the sausage, until browned, about 6-8 minutes. Add garlic and cook for 30 seconds.
1 tablespoon olive oil, 1 pound Italian sausage, ½ onion, 4 cloves garlic
Add gnocchi, chicken broth, cream, and Italian seasoning. Bring to a boil, stirring occasionally, then cover and cook for 5 minutes to cook the gnocchi.
16 ounces uncooked potato gnocchi, ½ cup chicken broth, 1 cup heavy cream, 1 teaspoon Italian seasoning
Add crushed tomatoes. Stir to combine. Add spinach and stir until it is wilted.
1 (28-ounce) can crushed tomatoes, 5 ounces fresh spinach
Season with salt, pepper, and red pepper flakes. Just before serving, sprinkle the freshly grated Parmesan cheese and basil over the top.
¼ teaspoon crushed red pepper flakes, kosher salt, freshly ground black pepper, ½ cup freshly grated Parmesan cheese, 2 tablespoons fresh basil