For the sausage and vegetables
01 -
1 tablespoon olive oil
02 -
1 lb (450 g) mild or hot Italian sausage, casings removed if needed
03 -
2 tablespoons unsalted butter
04 -
1 medium yellow onion, finely diced
05 -
2 medium carrots, finely diced
06 -
2 celery ribs, finely diced
07 -
4 cloves garlic, minced
08 -
1 teaspoon Italian seasoning
09 -
1/4 teaspoon red pepper flakes, optional
10 -
1/2 teaspoon kosher salt, plus more to taste
11 -
1/2 teaspoon black pepper
For the soup
12 -
2 tablespoons all-purpose flour
13 -
6 cups (1.4 L) low-sodium chicken broth
14 -
1 tablespoon tomato paste
15 -
1 can (14.5 oz/410 g) diced tomatoes, with juices
16 -
1 1/4 cups (150 g) ditalini or other small pasta
17 -
1 cup (240 ml) heavy cream
18 -
1 cup (90 g) freshly grated Parmesan cheese, plus more for serving
19 -
3 packed cups (90 g) baby spinach
20 -
2 tablespoons chopped fresh parsley, optional