Sausage and White Bean Soup with Parmesan Croutons

Ingredients

• • ¾ lb (340 g) mild Italian sausage meat (from about 3 sausages)
  • 3 tbsp (45 ml) olive oil
  • 2 tbsp (30 ml) tomato paste
  • 8 cups (2 litres) chicken broth
  • ⅓ cup (60 g) orzo
  • 3 slices country bread, each ¾ inch (2 cm) thick
  • 2 tbsp fresh Parmesan cheese, finely grated, plus more for serving
  • 2 cans (14 oz/398 ml each) cannellini beans, rinsed and drained
  • 6 cups (140 g) baby spinach