Finely dice the onion into 1/4-inch pieces, mince the garlic cloves, stem the kale and tear into small bite-sized pieces, and break the lasagna noodles into 1 to 2-inch pieces. Having everything prepped and ready before you start cooking ensures a smooth, efficient cooking process and prevents overcooking any components.

Heat the olive oil in a large pot over medium-high heat. Add the Italian sausage, breaking it up with a wooden spoon as it cooks, until it's browned and cooked through, about 7-10 minutes. Transfer the cooked sausage to a plate and set aside. I prefer Johnsonville mild sausage because it has better seasoning balance that won't overpower the delicate cream and kale in the final dish.

In the same pot with the sausage drippings, add the diced onion and a pinch of salt, cooking for 2-3 minutes until softened and fragrant. Add the minced garlic and Italian seasoning, stirring constantly for about 1 minute to bloom the spices and release their aromatics. Stir in the tomato paste and cook for another minute, then sprinkle the flour over the mixture and stir continuously for 1 minute to create a light roux that will thicken the soup without lumps.

Slowly pour in the broth while stirring constantly to prevent lumps from forming in the roux. Scrape the bottom of the pot with a wooden spoon to release any flavorful browned bits stuck to the surface. Bring the mixture to a boil over medium-high heat, then add the broken lasagna noodles. Cook the noodles for 8-10 minutes, stirring occasionally, until they're almost tender but still slightly al dente since they'll continue cooking as the soup simmers.

Reduce the heat to low and stir in the cooked sausage from Step 2, the half and half cream, and the kale torn from Step 1. Simmer gently for 10-15 minutes, stirring occasionally, until the kale is tender and the soup thickens to your desired consistency. I like to add the cream at the end rather than at the beginning because heating it gently prevents it from breaking or curdling, keeping the soup silky and smooth.

Taste the soup and adjust seasoning with salt, pepper, and red pepper flakes to your preference. Ladle the soup into bowls and top each serving generously with freshly grated Parmesan cheese, which adds both richness and a subtle salty depth that ties all the flavors together.