You can use almost any greens for this - kale, collards, spinach, beet greens, chard, etc.
Wash greens well and drain, then chop them and remove any tough, fibrous stems.
In a large saucepan, heat olive oil – enough to cover well the bottom of the pan – and add one or two chopped onions, and your choice of combination of spices such as chopped fresh ginger, ground coriander, ground cumin, garam marsala, turmeric, paprika, green chili, etc., and minced fresh garlic. Stir well and sauté for several minutes, stirring frequently, until onions are soft, and flavors are well incorporated.
Add chopped greens in handfuls, stirring well to incorporate between each batch. Sauté all together several minutes, stirring frequently. Cook until mixture is bubbly, and greens are just tender. Add a little water if needed.
Using an immersion blender, blender or food processor, purée the mixture. Serve hot in a bowl over cubes of Feta cheese. May also be served over cooked grains such as quinoa or rice.
Leftover, it makes a nice dip or spread.