01 -
Heat olive oil in a skillet over medium heat. Add Italian sausage and cook until browned, breaking it into small pieces.
02 -
Stir in minced garlic and red pepper flakes, if using. Cook until fragrant, about 1 minute.
03 -
Pour in chicken broth and heavy cream. Bring mixture to a gentle simmer.
04 -
Add penne pasta, cover, and cook for 10 to 12 minutes, stirring occasionally to prevent sticking, until pasta is tender.
05 -
Stir in chopped spinach until wilted. Mix in grated Parmesan cheese and season with salt and freshly ground black pepper to taste.
06 -
Sprinkle with chopped parsley or basil before serving.