Heat 1 tbsp. of oil in a soup pot over medium-high heat. Add the sausage and cook, crumbling it with a spoon, until browned. Add the onions, celery and carrots and cook until soft, about 5 minutes. Add all of the seasonings and toss to coat. Pour in the chicken stock, add the pumpkin puree and stir until well mixed. Add the zucchini, bring to a simmer and let cook until all the veggies are tender, about 15 minutes. Add the frozen spinach and heat through. Check seasonings, adjust if necessary, and serve.