Brown the Sausage: In a large pot over medium heat, add the Italian sausage. Cook until browned, about 5–7 minutes, breaking it up with a wooden spoon.

Sauté Onions and Garlic: Add the diced onion to the pot and sauté until translucent (about 3 minutes). As the onion softens, toss in the minced garlic and cook for an additional minute.

Pour in the Broth: Carefully add the chicken or vegetable broth, scraping the bottom of the pot to release any flavorful bits.

Simmer the Vegetables: Bring the broth to a gentle boil. Add the sliced carrots and dried oregano. Reduce the heat and let it simmer for about 10 minutes until the carrots are tender.

Add the Tortellini: Stir in the tortellini and cook according to package instructions (typically about 3-5 minutes).

Incorporate Spinach: Add the fresh spinach in the last minute of cooking. Stir until wilted.

Season to Taste: Taste the soup and adjust with salt and pepper. Optionally, sprinkle some Parmesan cheese into the pot.

Serve Warm: Ladle into bowls and sprinkle with additional Parmesan cheese and a drizzle of olive oil if desired.