Rinse the lentils.
Peel, trim, and cut the onion into large chunks. Peel and trim the garlic. Wash and cut the tomato into large chunks. Peel, trim, and dice the carrots into small cubes. Tie the parsley and cilantro sprigs together with kitchen twine.
In a blender or food processor, puree the onion, garlic, and tomato.
In a large, heavy pot, heat the olive oil over medium heat, add the puree, and sauté it until fragrant. Add the carrots and cook about 5 minutes, until the mixture is somewhat reduced enough to see the bottom of the pot when you stir.
Add the lentils, chicken broth, chopped ginger, cumin, harissa, salt, pepper, turmeric, saffron, and the fresh herb bouquet. Reduce the heat to low, and cook, covered, for about 45 minutes. Taste the lentils for doneness, and continue cooking, if necessary, until soft. Correct the seasonings, discard the herb bundle, and serve.