Heat the olive oil in a large Dutch oven or soup pot over medium heat.

Add the carrots, celery, and red onion. Season lightly with salt and pepper.

Cook slowly—this is not a stir-fry. Let the vegetables soften gently, stirring occasionally, for 10–15 minutes, until soft and translucent. This slow cooking is key to developing flavor.

Add the garlic and tomato paste. Stir and cook for 3–5 minutes over medium to medium-low heat, until fragrant and lightly golden. Season again lightly with salt and pepper.

Add the hot Italian sausage to the pot. Use a wooden spoon to break it up and cook until fully browned and cooked through, mixing it well with the vegetables.

Add the canned tomatoes to the pot. Use a handheld potato masher to gently mash the tomatoes until no large chunks remain.

Bring the mixture to a gentle boil, then reduce to a simmer and cook for about 5 minutes, seasoning again lightly with salt and pepper.

Stir in the sun-dried tomatoes, Italian seasoning, and Parmesan rind.

Fill the empty tomato can with water and add it to the pot. Then add the chicken stock and heavy cream. Stir well and bring everything to a rolling boil.

Once boiling, season the soup generously with salt—just like you would pasta water.

Add the ditalini pasta and cook according to package directions (about 10 minutes), stirring occasionally and scraping the bottom of the pot to prevent sticking.

Reduce the heat to a low simmer. Stir in the chopped baby spinach until wilted and fully incorporated. As the pasta cooks, it releases starch, creating the most beautifully creamy texture.

Taste and adjust seasoning with additional salt and pepper if needed.

Serve hot topped with shaved Parmesan and fresh parsley.