I cook by eye, feel, and taste, so all measurements have been recreated by memory. If it doesn't work, let me know.
1 pound brown lentils (or Lentilles de Puy if you can get them)
Good Spanish olive oil
2 small onions, diced
4 carrots, peeled and diced
3 celery stalks, diced
2 cloves garlic, minced
bouquet garni (parsley, thyme sprigs, bay leaves, peppercorns, bundled & tied in cheesecloth)
2 t. salt, or more
1/4 t. Spanish smoked paprika
2 quarts chicken or vegetable stock
1 14 oz. can diced tomatoes, undrained
1/2 lb. smoked chorizo (can substitute kielbasa for a less spicy soup), sliced in half lengthwise and then into half moons.
chopped fresh parsley to garnish
grated parm-reg or aged manchego
Heat the olive oil in a large saute pan. Saute onion, carrot, and celery in the oil until softened but not browned. Pick over lentils and put them in a large soup pot or dutch oven. Add the vegetables, garlic, bouquet garni, and stock to the lentils, and bring to a simmer over high heat. Turn heat down and simmer for half an hour.
While the lentils are cooking, heat the saute pan again and add the sausages. Cook over medium-low heat until most of the fat is rendered and sausages pieces start to brown. drain on paper towels.
Add the canned tomatoes, paprika and salt to the lentils, and simmer another half an hour. Add sausages. Taste, and add salt and freshly ground pepper as needed. Fish out the bouquet garni and discard. Add 1-2 tablespoons of sherry vinegar just before serving.
Some people like to use a stick blender to puree the soup. I don't. A little grated Parm, or aged Manchego on top is good, but not necessary. Sprinkle with chopped fresh parsley. Serves a lot.