Add the potato, carrots, tomatoes, onion, garlic, and lentils to a large pot over medium heat with 2 cups water or broth (about 480 ml).

Once the vegetables are tender, blend the mixture with an immersion blender or in a regular blender until smooth and well combined.

Return the mixture to the pot over low heat. Add salt, cumin, and 3 cups water or broth (about 720 ml). Stir continuously and do not cover the pot.

In a skillet over medium heat, add 4 tablespoons corn oil and the vermicelli noodles. Stir until the noodles turn golden brown, then immediately add them to the lentil soup on the stove.

Stir occasionally to prevent sticking or burning. Continue stirring until the vermicelli is cooked through, then serve.