In a cooking pot, heat olive oil at medium high. Add chopped onions and sauté until softened, about 5 minutes. Then add garlic and ginger. Stir and cook until fragrant, about 1 minute.

Add diced potatoes and cook for 2 minutes.Then add turmeric, ground cumin, ground coriander and paprika. Stir and cook until aromatic, about 30 seconds.

Next add chopped mustard greens and sauté until slightly wilted, about 3 minutes. Add chopped spinach and continue to cook the greens until wilted, about 5 minutes. Tip: Do not overcook the greens, which will help retain the bright color.

In a skillet, melt the butter at medium heat. Add flour and cook until very lightly toasted, stirring continuously, about 2 minutes. Add the milk in a stream, whisking until well combined. Cook the mixture until thickened, stirring in between, about 2 minutes.

Add the thickened milk to the cooked greens. Stir in salt and adjust to taste. Transfer the mixture to a high speed blender and blend until pureed, about 3 minutes. Tip: The mustard greens are tougher than spinach, so blending them to a smooth consistency will take a few minutes.

Pour the creamy soup back into the cooking pot and quickly heat it. Tip: Do not simmer for too long, because the greens will overcook or the soup may boil over.

Transfer the soup to a serving dish. Drizzle with cream, olive oil and sprinkle freshly ground black pepper or mild red pepper flakes. You can also top with buttered croutons. Serve the soup immediately with bread or corn chips.