Step 1: Brown the Sausage

1. Heat the Oil: In a large pot or Dutch oven, heat 1 tablespoon of olive oil over medium heat.
2. Add the Sausage: Add the spicy Italian sausage to the pot, breaking it up with a wooden spoon as it cooks. Cook for about 5-7 minutes, or until the sausage is browned and cooked through.
3. Remove Excess Grease: If there’s a lot of grease in the pot after browning the sausage, you can carefully drain some of it, leaving just enough to sauté the vegetables. The rendered fat adds flavor, so leaving a small amount is ideal.
4. Set the Sausage Aside: Once the sausage is cooked, use a slotted spoon to transfer it to a plate, leaving the remaining oil and fat in the pot.

Step 2: Sauté the Vegetables

1. Add the Onion, Carrot, and Celery: In the same pot, add the diced onion, carrots, and celery. Cook for about 5 minutes, stirring occasionally, until the vegetables start to soften.
2. Add the Garlic and Spices: Add the minced garlic, Italian seasoning, and crushed red pepper flakes (if using) to the pot. Cook for another 1-2 minutes, stirring constantly, until the garlic is fragrant.

Step 3: Build the Broth

1. Add the Broth and Tomatoes: Pour in the chicken broth and add the can of diced tomatoes with their juices. Stir to combine and scrape up any browned bits from the bottom of the pot, which adds flavor to the broth.
2. Return the Sausage: Add the cooked sausage back into the pot. Stir to incorporate.
3. Simmer the Soup: Bring the soup to a gentle simmer. Cover the pot and let it cook for about 10-15 minutes, allowing the flavors to meld together.

Step 4: Add the Tortellini and Spinach

1. Add the Tortellini: Stir in the fresh tortellini and cook for 5-7 minutes, or until the tortellini is tender and cooked through. If using frozen tortellini, cook according to package instructions, as it may take slightly longer.
2. Add the Spinach: Add the baby spinach to the pot and stir until it wilts, about 1-2 minutes.
3. Add the Cream: Pour in the heavy cream and stir to combine. The cream adds richness and balances the spice from the sausage.
4. Season to Taste: Taste the soup and adjust the seasoning with salt and pepper as needed.

Step 5: Serve and Garnish

1. Serve Hot: Ladle the soup into bowls, making sure each bowl gets plenty of sausage, tortellini, and vegetables.
2. Garnish: Top each bowl with a sprinkle of freshly chopped basil or parsley, grated Parmesan cheese, and a pinch of crushed red pepper flakes if desired.
3. Serve with Bread: Serve with crusty bread or garlic bread on the side for dipping into the flavorful broth.