Start by browning the sausage in a large saucepan over medium heat. The sausage will release its fat and begin to crisp up, creating a deep, savory base for your soup. This step adds so much flavor and richness to the final dish.

Once the sausage is cooked through, toss in the chopped onion. Sauté it with the sausage until it softens, allowing the onion to caramelize slightly and develop sweetness. This is the moment the savory smells in your kitchen will start to lure everyone to the dinner table!

Add the garlic and spinach to the mix. Stir until the spinach wilts down. It only takes a minute, but this is when your kitchen will start to smell absolutely amazing. The garlic adds depth, while the spinach brings a pop of freshness to balance the richness of the sausage.

Pour in the chicken broth and bring the mixture to a simmer. Let it cook for about 5 minutes. This gives all the flavors time to meld together, making a fragrant base for your soup.

Now, break the lasagna noodles into pieces (about 2-3 inch chunks) and add them to the soup along with your Italian seasoning. The noodles will soak up the rich broth and turn into soft, delicious bits of "lasagna" in each bite. Let the soup simmer until the noodles are tender, about 10-12 minutes.

While the soup is simmering, it’s time to make the creamy Alfredo sauce. In a separate skillet, melt butter over medium heat. Once the butter is melted, whisk in the flour and cook for 1-2 minutes to form a roux. Slowly add the milk while whisking continuously to prevent lumps. Continue stirring until the mixture thickens, about 3-4 minutes. Finally, stir in the Parmesan cheese until the sauce is smooth and velvety.

Once your Alfredo sauce is ready, pour it into the soup and stir to combine. The sauce will blend perfectly with the broth, creating a rich, creamy consistency that coats the noodles and sausage. Let the soup cook for another 2-3 minutes to bring everything together. Serve hot, and enjoy the creamy, comforting goodness of this lasagna-inspired soup.