Spinach - I saute some minced garlic and chopped onion in olive oil, then add the spinach with a little water and let it wilt and cook. Then add some raisins (and toasted pine nuts if desired).
Bok Choy -Saute some minced garlic in olive oil, add Bok Choy and some water and cover. Cook till tender. Add some oyster sauce.
And of course, you can always google recipes for all of the greens.