Rinse the red lentils thoroughly under cold water until the water runs clear.
In a large pot, heat the olive oil over medium heat.
Add the chopped onion and sauté until it becomes translucent, about 5 minutes.
Add the minced garlic and diced carrot, and cook for another 3 minutes.
Stir in the chopped tomato and cook until it softens, about 5 minutes.
Add the rinsed lentils to the pot and stir well to combine with the vegetables.
Pour in the vegetable broth and bring the mixture to a boil.
Reduce the heat to low, cover the pot, and let it simmer for about 20-25 minutes, or until lentils are tender.
Stir in the ground cumin, ground coriander, turmeric powder, salt, and black pepper.
Cook for another 5 minutes to allow the flavors to meld together.
Remove from heat and stir in the lemon juice.
Garnish with fresh cilantro before serving.