How to Make It
In a heavy medium saucepan, heat 2 tablespoons of the oil. Add the diced fennel, onion, carrot and celery and cook over moderately high heat until the onion is softened but not browned, about 5 minutes. Add the lentils and stir to coat with the oil. Add 2 1/2 cups of water and bring to a simmer. Cover partially and cook over moderately low heat, stirring occasionally, until the lentils are tender and the liquid is absorbed, about 40 minutes.
Meanwhile, preheat the oven to 450°. In a medium saucepan, boil the wine until reduced to 6 tablespoons, 10 to 12 minutes. Remove the pan from the heat. Whisk in the vinegar, 1/2 cup of the oil, 1 1/4 teaspoons of salt and 1/2 teaspoon of pepper. Add the vinaigrette to the lentils and cook over low heat, stirring occasionally, for 5 minutes.
In a large ovenproof skillet, heat the remaining 2 tablespoons of oil. Season the meat with salt and pepper and rub with the ground cumin and fennel. Put the pork in the hot skillet and sear until well browned on all sides, about 6 minutes. Place the skillet in the oven and cook for 5 minutes. Let the pork stand, covered, for 5 minutes, then slice and serve on top of the lentils.