In a large pot, heat the oil over high heat.

Add the leek, and sauté until it just begins to brown, three to four minutes.

Add the cauliflower, garlic, ginger, turmeric, salt, pepper, and cumin and sauté to lightly toast the spices, one to two minutes.

Add the broth and bring to a boil.

Reduce the heat to a simmer and cook until the cauliflower is tender, about five minutes.

Using an immersion blender, purée the soup in the pot until smooth.

Stir in the coconut milk and cilantro, heat through, and serve.