2 tablespoons unsalted Butter
2 tablespoons Vegetable oil
1 medium onion, coarsely chopped
2 tablespoons coarsely chopped Garlic
4 slices of Bacon, coarsely chopped
1 pound callaloo (see Note) or Spinach, stemmed, leaves cut into 1/2-inch ribbons
1/2 cup plus 2 tablespoons Basil
1/2 cup flat-leaf Parsley leaves
2 tablespoons Celery leaves
4 cups water
1/2 cup heavy cream

1. In a large saucepan, melt the Butter in the oil. Add the onion and cook over moderate heat until softened, about 3 minutes. Add the Garlic and cook, stirring, until softened but not browned, about 2 minutes. Add the Bacon and cook, stirring frequently, until the fat is rendered, about 5 minutes. Add the callaloo, Basil, Parsley and Celery leaves and cook over moderately high heat, stirring occasionally, until the greens are wilted and barely tender, about 7 minutes.
2. Add the water to the saucepan and bring to a boil. Cover and cook over moderate heat until the greens are soft, about 10 minutes. Puree the soup in batches in a blender until perfectly smooth. Return the soup to the saucepan; add the cream and season with Salt and pepper. Bring to a simmer and then serve in soup plates.