Heat oil in a large stock pot over medium-high heat and add diced onion. Cook onions for 4 to 5 minutes then add minced garlic, parsley and curry powder (add ginger at this time too if using). Cook for 2 minutes until garlic and curry become fragrant.
Add diced pumpkin, cauliflower, lentils, vegetable broth and water to the pot. Bring everything to a boil, then reduce heat and simmer, stirring occasionally, for 20 minutes until lentils and pumpkin are tender. Use an immersion blender to blend soup until smooth. Alternatively blend in a blender in batches.
Add coconut milk to soup and allow to simmer for 10 more minutes. Season with salt to taste and serve with fresh parsley.