I use a dutch oven for this recipe - you can use any soup pot. The oil gets added to the pot over medium heat. Then we add the sausage until mostly cooked through.
Then we add in the aromatics (carrots, onion, celery & garlic) these get cooked with the sausage for about 3 minutes. This helps them start to develop flavor and soften a bit.
The remaining ingredients (except coconut milk and spinach) get added in. We bring this to a boil and then reduce to a simmer for 15-20 minutes. Then discard bay leaves and rosemary sprig.
The last step is to stir in the coconut milk (or cream if using) and the fresh spinach. The spinach will wilt perfectly into the hot soup. Remove from heat and serve!