In a saute pan, heat the oil with the garlic and mustard seeds until the garlic is almost caramelized. (Watch those mustard seeds; they pop. I use one of those screens.) Add the greens and cook covered, just until wilted. Sprinkle with salt and pepper to taste. Serves 2.
This is wonderful with steak and baked potatoes. I prefer arugula or rapini but some people find them to be too bitter.