Easy Italian Sausage and Bean Soup

olive oil

mild Italian sausages, casings removed

medium onion, chopped

garlic, minced

medium carrot, chopped

celery stalk, chopped

dried oregano

dried basil

dried thyme

cannellini beans, drained and rinsed

low-sodium chicken stock

Salt and freshly ground black pepper,

raw spinach, chopped

Parmesan cheese, for topping