Lentils are a recent and post-Hispanic addition to the Mexican larder but they have made themselves very much at home and team up regularly with more native ingredients, particularly during Lent, La Cuaresma, in the spring and the DÃas de los Muertos, Days of the Dead, in November. In Oaxaca, the cooks like to add fruit to their lentil soup, chiefly pineapple and plantain, providing sparkle and richness as well as balancing the acidity of the tomatoes and heat of the chillies.
Lenten Cooking in Mexico - Lentil Soup Recipe