Rinse the lentils, then add the potato, tomato, and carrots. Place them in a pot with the water and cook over heat until everything is tender. Turn off the heat and let cool, then blend the mixture until smooth.

Toast the vermicelli noodles in a pan until golden. Add the blended mixture to the noodles, then season with salt, black pepper, cumin, and paprika if desired. Cook over low heat, stirring every few minutes to prevent the noodles from sticking.

Sauté the onion until it starts to brown, then add the garlic and cook together briefly. Add this mixture to the soup when the noodles are halfway cooked. Let everything simmer until the noodles are fully cooked. If the soup becomes too thick, add a little hot water. Turn off the heat when done.