In a large pot or Dutch oven, heat over medium-high flame. Add 1 pound of mild Italian sausage and cook for 6-8 minutes, breaking it up with a spoon until nicely browned. Remove the sausage and leave about 2-3 tablespoons of rendered fat in the pot.

With the remaining fat in the pot, add diced yellow onion, diced celery, and sliced carrots. Sauté for 8-10 minutes until the onions are soft and translucent. Add minced garlic and cook for another minute.

Stir in 1 tablespoon of tomato paste, cooking for 1-2 minutes until it darkens slightly. Add 1 teaspoon of Italian seasoning, ½ teaspoon of crushed red pepper, and ½ teaspoon of ground black pepper. Stir for about 30 seconds.

Pour in 4 cups of chicken broth and scrape the bottom of the pot. Bring to a boil, then reduce the heat to low, cover, and let it simmer for 15-20 minutes.

Add the drained and rinsed Great Northern beans and browned sausage back into the pot. Let everything simmer for another 5-7 minutes, and then stir in 2 cups of fresh baby spinach until wilted.

Stir in ½ cup of heavy whipping cream until fully incorporated. Adjust seasoning if needed, and serve the soup in bowls garnished with fresh chopped parsley.