How to Make It
In a medium heavy soup pot, combine the lentils with the chicken stock. Cover and bring to a boil.
In a food processor, pulse the carrot, celery, quartered onion and the garlic until finely chopped. In a large skillet, heat 1 tablespoon of the oil. Add the vegetables and the thyme and cook over moderately high heat until softened, 3 minutes; scrape into the lentils, cover and cook over moderate heat until the lentils are tender, 20 minutes. Stir in the spinach; season with salt and pepper.
Meanwhile, heat the remaining 1 tablespoon of oil in the skillet. Add the onion wedges and sausages and cook over moderate heat, turning occasionally, until the onions are softened, 8 to 10 minutes. Add the balsamic vinegar and cook for 1 minute.
Thickly slice the sausages. Stir the sausages, onions and any accumulated juices into the lentils; discard the thyme sprigs. Spoon the lentils and sausages into bowls and serve.
One serving 494 cal, 24 gm total fat, 4.8 gm saturated fat, 39 gm carb, 9 gm fiber.