Heat olive oil in a large pot over high heat. Add the sausage and sear for about one minute per side. Crumble and cook until deeply browned for maximum flavor. Remove with a slotted spoon to a paper towel-lined plate, reserving 2–3 tablespoons of the drippings.

Toss in the chopped onion, celery, and carrot, stirring them into the pot. Cook for 7–9 minutes, stirring occasionally, until the vegetables are soft. Stir in the minced garlic and sauté for 30 more seconds.

Stir in salt, pepper, Italian seasoning, parsley, oregano, and thyme. Mix well, then add butter and stir until fully melted.

Sprinkle in the flour and whisk continuously for 1 minute to cook off the raw flavor. Slowly add the chicken broth, whisking to create a smooth, slightly thickened base.

Gradually stir in the milk and heavy cream. Bring the soup to a gentle boil.

Reduce the heat to medium. Add the gnocchi, kale or spinach, and the browned sausage. Simmer for 2–4 minutes until the gnocchi is tender.

Taste and adjust the seasonings if needed. Ladle into bowls, garnish with fresh thyme, and serve with hearty buttered bread.