Wash and rinse lentils. Soak in a large ceramic or glass bowl covered with at least one inch of water for 2-4 hours.
Finely cut the carrots, celery, onion, and leek into small pieces. Dice the 2 potatoes into bite-sized pieces and set them aside.
Heat olive oil in a large saucepan over medium heat and fry the bacon. When the bacon is fried, add onion, celery, and carrots and stir fry for about 5 minutes, until the onions are translucent.
Drain the lentils, rinse and add to the pot with the marjoram, and bay leaf. Add the broth and stir everything together. Bring to a boil and simmer with the lid on for 20-30 minutes.
Flavor the soup with salt, pepper, sugar, and additional marjoram to taste. Add the diced potatoes and continue cooking the soup for approximately 20 minutes, until the potatoes are cooked.
Cut the frankfurters into bite-sized pieces and add them to the lentil soup to warm them up. Serve the soup and garnish with chopped parsley. Enjoy!
Notes
Gluten Alert! Be sure to check that the labels on the broth and European Wiener sausages you are using are gluten-free if you are following a gluten-free diet. Feel free to substitute the European Wiener sausages (frankfurters) with gluten-free hotdogs.