Heat a skillet over medium high heat.
Add oil and onion and sauté 2 minutes.
Add cabbage and turn in pan, sautéing it until it wilts, 3 to 5 minutes.
Add vinegar to the pan and turn the cabbage in it. Season with mustard seed and pepper and reduce heat a bit.
Let cabbage continue to cook 10 minutes or until ready to serve, stirring occasionally.
From Yasamin Soltanian, The GW Healing Clinic