This delicious lentil soup is flexible and scalable. That means you can substitute the aromatics and add fresh vegetables. The recipe is designed for batch cooking so you can serve a crowd or freeze the leftovers. You can scale up the recipe further if your soup pot is large enough. Enjoy with toppings like crème fraîche or serve with crusty bread.
Cover the lentils with water in a mixing bowl and soak for at least 2 hours. You can soak the lentils overnight if you remember. I read that you don't need to soak green lentils but I've never tried cooking without soaking.
While the lentils are soaking, prepare your spice sachet. Wrap your spices in a neat package.
Chop the carrots, onions, garlic, (if using) bell peppers/capsicum, celery, and other aromatics and vegetables you want to add to the soup. You can slice the vegetables into relatively large pieces if you are short on time.
Heat the oil in a big soup pot on high heat. Add the onions and cook until translucent, about 5 to 10 minutes. Keep stirring to avoid burning the onions.
Add the chopped carrots, bell peppers, garlic, celery, and all remaining aromatics or vegetables (except tender greens) to the soup pot. Cook for 3 minutes while stirring with your spatula or wooden spoon to avoid burning the vegetables.
If adding sausages, make a well in the soup pot by pushing aside the vegetables. Add the sausages and brown them on the outside for 3 to 5 minutes. I like to cut up the sausages, especially if they are raw, with a pair of scissors to allow the flavors to blend better.
Add the lentils and (if using) the tomato paste to the soup pot.
Add the broth, salt, and spice sachet to the soup pot. Fill the carton of broth with water and add to the soup pot. Keep adding water until the lentils are fully covered with liquid (you could end up adding as much as 1 to 2 L of water). Allow the soup to come to the boil. Turn the heat to low to simmer once the soup has boiled. Stir to mix. A simmer looks like small bubbles coming to the surface periodically but there is no active boiling happening. Simmer for 3 to 4 hours on low. After 3 hours of simmer, eat a lentil. If its texture still tastes tough, cook for another 30 minutes. Keep testing in 30-minute increments until the lentils taste tender.
When your lentils are tender, you can add potatoes or green vegetables to cook. Once everything is cooked, your lentil soup is ready to serve. Enjoy!