In a medium-size saucepan sauté the onion, ginger, and garlic in the olive oil until tender. Add the pumpkin puree, chicken broth, cinnamon, sugar and freshly grated nutmeg. You can use regular nutmeg to substitute the freshly grated nutmeg. Simmer all the ingredients for about 15-20 minutes. Gradually add the milk the last 5 minutes of cooking. Add salt and pepper to taste.