This is an easy, last minute dinner since you might have many of the ingredients on hand. If you don't have any swiss chard, kale, spinach and arugula also work great. If you use kale, I recommend removing the tough central stem. If you use either arugula or baby spinach leaves, you don't need to precook them at all; just toss them in at the end. The warmth of the pasta will sufficiently wilt them.