Lentils with Merguez Sausages

In order to stay within the spirit of this book, you must make this dish with a jar or tin of lentils, or when you have some leftover cooked lentils. This recipe is adapted from one in Annie Bells excellent book Evergreen, now sadly out of print, for a vegetarian dish that she serves with Colcannon, a traditional Irish dish of potatoes and cabbage.