1-First Step: Prep and mise en place Gather ingredients and tools first. Dice the onion, chop the carrots and celery, and mince the garlic. If using sausage links, remove casings so the meat can crumble evenly. Measure the pasta and have the canned tomatoes and broth nearby. This small prep stage cuts overall cook time and keeps the flow smooth when cooking in a single pot.

2-Second Step: Brown the sausage Heat a large pot or Dutch oven over medium-high heat. Add the sausage (removed from casings) and cook, breaking it up with a spoon until browned and cooked through, about 5 to 7 minutes. Remove the browned sausage and set it aside, leaving 1 tablespoon of grease in the pot. If there isn’t enough fat left, add a splash of olive oil. Browning the sausage develops Maillard flavors that deepen the soup’s taste.

3-Third Step: Sauté the vegetables In the reserved fat, add the diced onion, chopped carrots, and chopped celery. Sauté until the onions are translucent and the carrots start to soften, about 5 minutes. Add the 4 minced garlic cloves and cook until fragrant, roughly 30 to 60 seconds. This step unlocks sweetness from the vegetables and milks rich flavor into the fat, building a flavorful base for the broth.

4-Fourth Step: Build the broth Stir in the one 15-ounce can diced tomatoes with juice, 5 cups bone broth or chicken broth, and 1 tablespoon Italian seasoning. Return the browned sausage to the pot and bring everything to a boil. Using bone broth adds extra body and minerals, while chicken broth gives a lighter profile. If you are using low-sodium stock, you can adjust salt at the end.

5-Fifth Step: Cook the pasta in the soup Once the pot is boiling, add 1.5 cups dried shell pasta. Reduce the heat to a simmer, cover the pot, and cook until the pasta is al dente according to package directions usually about 8 to 12 minutes depending on pasta shape and brand. Stir occasionally to stop the pasta from sticking to the bottom and to check doneness. Cooking the pasta directly in the soup saves a pot and lets the pasta soak up flavor.

6-Sixth Step: Finish with spinach and seasoning When the pasta is cooked, stir in 2 cups baby spinach and cook until wilted, about 30 seconds. Taste and season with salt and black pepper to taste. If using, ladle into bowls and top with optional grated Parmesan cheese and a pinch of red pepper flakes for garnish. Serve hot with garlic bread or a simple side salad.

7-Final Step: Serving and timing tips Serve immediately for best texture. Prep Time totals 35 minutes (10 minutes prep and 25 minutes cook). If making for a crowd, double the recipe and use a larger pot. For busy evenings, do vegetable chopping ahead of time and store in a sealed container in the fridge; brown the sausage and finish the soup when you are ready to eat. For reheating, see the storage section for best practices.