Coconut Pumpkin Soup

Name: Coconut-Pumpkin Soup
Ingredients: 1 teaspoon black mustard seeds; 2 sprigs of curry leaves; olive oil; 1 small onion, chopped finely; 1 teaspoon garlic, chopped finely; 1 tablespoon ginger, chopped finely; 1/2 tablespoon turmeric powder; 1/2 teaspoon cayenne; 1 1/2 cups pumpkin, mashed; 1 can low-fat coconut milk; salt and pepper to taste; fresh coriander leaves for garnishing