1 bunch greens of your choice
Wash the greens (works with spinach, chard, kale, collard greens, beet greens, bok choy, watercress, etc.). If they have a lot of stem, chop the stems and keep separate. Chop the leaves coarsely (chunks can be easily half the size of your hand, no need to chop small). Chop some garlic (say 1 or 2 cloves for an average bunch of greens).
Heat a dry wok on high. Add some vegetable oil (not olive oil, as it will smoke at this heat) and add a pinch of salt into the oil (this is important). Throw in the garlic and cook until *just* beginning to brown, then immediately throw in the greens and stir. (If you had a lot of coarse stems, cook these first until they begin to soften.) Don't add water, just the water clinging to the leaves is enough.
Stir and fry on high heat until the greens are completely wilted. Add a dash of soy sauce (tamari is nice) and a dash of vinegar (rice vinegar is nice).
Serve immediately. If you like, garnish with toasted sesame seeds for even more calcium.