For serving: chopped cilantro, sumac, crushed red pepper, lemon wedges, pita bread or rice
Place a stockpot over medium heat and add the olive oil. Stir in the onion, carrots, and garlic, and cook for about 10 minutes, stirring every minute or two, until they soften.
Once the veggies soften, stir in the cumin and coriander seeds, and cook, stirring constantly, for another 2 minutes.
Stir in the tomato paste and continue to cook, stirring constantly, for another minute.
Add the vegetable broth, lentils, dried mint, paprika, sumac, and cayenne pepper. Stir together, cover, and increase heat to high. Once it comes to a boil, reduce the heat to low and continue to cook, covered, for about 10 minutes, until the lentils are starting to fall apart. *
Taste the soup and add more salt if necessary. If the soup looks a little dry add 1/2 cup of water at a time. Partially purée the soup, if desired. Once you’re happy with the seasoning and amount of liquid, stir in the lemon juice.
Serve either hot, chilled, or at room temperature. Garnish with cilantro, sumac, and crushed red pepper. Serve alongside lemon wedges and bread or rice.
* Most red lentils sold in US grocery stores are split red lentils. The lentils should be falling apart and past al dente.