Penne tossed with spring vegetables, such as carrots, morel mushrooms, asparagus, peas and fava beans, along with loads of fresh herbs is a perfect example of Mario Batali's rustic approach to great-tasting Italian food. When both fava beans and morel mushrooms are in season, by all means use them in this recipe. But if you can't find either of those, substitute what looks best. Basic cremini mushrooms will work and frozen lima beans are a good option. Recipe adapted from Molto Gusto by Mario Batali and Mark Ladner (Ecco/HarperCollins Publishers, 2010).