Place the cashews in a small bowl. Pour over enough boiling water to cover the cashews. Soak while you prep everything else, about 15 minutes. Drain before using.

Heat the olive oil in a large Dutch oven or pot over medium-high heat. Add the leeks and sauté until they are softened and starting to brown, about 4 minutes. Add the garlic, thyme, oregano and red pepper flakes (if using), and cook, stirring frequently, about 1 minute.

Pour in the vegetable broth and deglaze the pot, stirring up any browned bits. Add the soaked and drained cashews, cauliflower florets, salt and pepper to taste. Add enough water to cover the cauliflower (at least 1 cup for a thick soup, but you can add more if you want a thinner texture).

Bring the soup to a boil, then reduce the heat to maintain a rapid simmer and cook until the cauliflower is tender, 10 to 15 minutes.

While the soup is simmering, chop the kale into thin strips. Set aside.

Heat a large skillet over medium heat. Once hot, crumble the vegan sausage into the pan and stir occasionally, until the sausage is browned. Alternatively, slice the sausage into discs and sear on both sides. Remove from the heat and set aside.

When the soup is done cooking, transfer to a blender (working in batches as needed) and blend it until thick, creamy and smooth. Remove the center cap on the blender lid and cover it with a dish towel to allow the steam to escape while blending. (Alternatively, use an immersion blender.)

Return the pureed soup to the pot and return to a simmer. If it is too thick, add more water to thin. Add the sliced kale and browned sausage, and simmer until the kale is tender and wilted, about 3 minutes. Squeeze in some lemon juice, if using. Taste for seasoning, adding more salt and pepper as needed.

Serve each soup bowl with a drizzle of extra virgin olive oil, and if desired, fresh thyme and parsley.