Combine the feta cheese and olive oil into a food processor, and process until it forms a smooth paste and begins to clump together.
Spoon the yogurt into a medium mixing bowl. Grate the lemon zest over the yogurt, and then cut the lemon crosswise and squeeze the juice into the bowl. Spoon in the feta paste, salt, green onions, garlic, parsley, dill, chives and black pepper. Fold them together until incorporated into the yogurt, and serve.