Spicy Yellow Indian Cabbage

* 1/3 cup oil * 1-1/2 teaspoons yellow or brown mustard seeds * 5 cloves garlic, thinly sliced * 1-1/2 teaspoons ground turmeric * about 1-1/2 pounds cabbage, cored and thinly sliced * 1 teaspoon salt * 1/2 teaspoon ground cayenne pepper