Heat 1 tablespoon of olive oil on medium heat in a large, high-sided, heavy-bottomed skillet on the stovetop.

Add crumbled sausage and cook on medium heat for about 5 minutes, crumbling it, until it is cooked through. Drain any grease or liquid.

To the same skillet with sausage, add uncooked rigatoni, chicken broth, heavy cream, minced garlic, Italian seasoning, and tomato sauce.

Bring to a boil on medium heat and stir everything well. Cover with a lid, and allow the pasta to cook for about 10 to 15 minutes on medium heat, while the sauce boils.

Cook until pasta reaches an 'al dente' texture. Stir frequently to prevent pasta and sausage from sticking to the bottom of the pan.

Add fresh spinach, and cook on medium heat, stirring frequently for a couple of minutes, until the spinach wilts to your liking.

Alternatively, just remove the skillet from heat, top sausage rigatoni with spinach, cover the pan with the lid. Let the spinach wilt, off heat, in the residual heat in a covered skillet for about 4 minutes. Then, stir.

Cook longer if you would like a thicker sauce.

Mix everything well. Remove from heat. Season with salt, freshly ground coarse black pepper, and red pepper flakes if you like.