Scoop yogurt into a paper towel lined strainer set over a bowl.
Let stand at room temp for 30 minutes.
Meanwhile, heat the olive oil in a small skillet. Add the pine nuts and minced onion and cook over high heat, stirring frequently until the onion is softened and lightly browned and the pine nuts are golden, 4 to 5 minutes.
Add the cumin, coriander, chile powder and cayenne, cook, stirring for 1 minute. Place in a bowl.
Using your hands or a potato ricer, squeeze the spinach until very dry. (I've never used that technique before, I place spinach in a clean dish towel and squeeze dry).
Add the spinach and the drained yogurt to the onion mixture, season with salt and stir well.