This is from a post on Reddit, it includes a detailed discussion of the history and variations in lentil soup throughout the Mideast, where it is extremely popular in pretty much all countries. His version completely blends the soup with a stick blender until it has the texture of smooth thick cream.
Ingredients
1.25L (1.25 qt) Vegetable stock, you can also use chicken, meat or even water. If you are using stock cubes rather than fresh stock, then please use high quality ones.
250g (1/2 lb) Split Red Lentils (he emphasises using red, not green or yellow)
150g (5 1/4 oz) Carrots (about 1 large or 2 medium)
1 Brown Onion
1 Tomato
4-6 Garlic Cloves
1/2 Cup Short Wheat Vermicelli
3 Tbsp White Vinegar
1 1/2 Tbsp Olive Oil
1 1/2 Tsp Salt
1 1/2 Tsp Ground Cumin
1/2 Tsp Ground Black Pepper
1/4 Tsp Chili powder (cayenne or whatever you have on hand)
Instructions
1. Peel and slice your carrots into large chunks about 1 cm or 1/2 an inch thick. Peel your onion, remove the root and top and slice into quarters. Wash your tomato and slice into quarters, we'll remove the skin later.
2. Peel your garlic cloves, mince 2 of them and set aside, the rest should be lightly crushed
3. Add your chopped vegetables, the lentils and garlic (the crushed ones not minced) to a large stock pot. Add your stock or water to the pot as well as 1 teaspoon of cumin, turn the heat up to high and bring the pot to a boil.
4. When the pot boils, retrieve the tomato quarters and remove their skin, then add them back to the pot. Turn the heat down to low and allow the soup to simmer for 45 minutes. When done simmering, the carrots should be cooked through and the lentils should be swollen and mushy.
5. Using an immersion (stick) blender, blend the soup and all the vegetables pieces into a uniformly smooth mixture. Once blended it will have a creamy texture that resembles wall paint, remove the soup from the heat and set aside
6. In a small pot add 1/2 a tbsp of olive oil on medium high heat and add the 2 minced garlic cloves to it. Fry for about 30 seconds then add the remaining cumin. Fry for another 15 seconds then add the vinegar. Mix and fry for 15 more seconds and add pour the mixture into the lentil soup
7. Add salt, pepper and Chili powder (optional) then mix the soup well. Taste your soup and check for seasoning, you may need to add another 1/2 tsp of salt if your stock is low in sodium, or add more Chili powder if you'd like it spicier
8. In a pot add the remaining olive oil and the vermicelli and fry on medium high heat until it turns a golden color. Stir constantly as it can burn easily
9. Add the fried vermicelli to the soup as well as 1 cup of water to thin the soup out. Bring the pot to a boil once more and allow the vermicelli to cook for 10 minutes
10. When the time is up, your soup is ready. The vermicelli will have absorbed some water from the soup, so add more water to thin it out until it's thinner than the paint like texture from before. It should be able to coat the back of a spoon without running, similar to the consistency of cooking cream. Garnish with coriander, thin slices of Chili and nigella seeds