In a large pot, heat olive oil over medium heat. Add Italian sausage and cook until browned, breaking it up with a spoon. Remove excess fat if necessary.

Add chopped onion and minced garlic to the pot, and cook until the onion is translucent, about 3-4 minutes.

Pour in the chicken broth and diced tomatoes, and bring to a simmer.

Stir in heavy cream, grated Parmesan cheese, and Italian seasoning. Simmer for 10 minutes, stirring occasionally.

Add baby spinach and cook until wilted, about 2 minutes.

Season with salt and pepper to taste.