The pea has been cultivated for around 9,000 years and spread quite early from the Middle East to the Mediterranean, India, and China. It’s a cool-climate legume that grows during the wet Mediterranean winter and in the spring of temperate countries. It was an important protein source in Europe in the Middle Ages and later, as the old children’s rhyme attests: “Pease porridge hot, Pease porridge cold, Pease porridge in the pot, Nine days old.” Today, two main varieties are cultivated: a starchy, smooth-coated one that gives us dried and split peas, and a wrinkly type with a higher sugar content, which is usually eaten when immature as a green vegetable. Peas are unusual among legumes in retaining some green chlorophyll in their dry cotyledons; their characteristic flavor comes from a compound related to the aroma compound in green peppers (a methoxy-isobutyl pyrazine).