Rinse the lentils in cold water until the water runs clear, then set aside.
Dice the onion and mince the garlic, preparing them for sautéing.
Heat a dry skillet over medium heat, then add the diced onion and minced garlic, cooking until fragrant and translucent, about 5 minutes. This deepens their flavor and fills the kitchen with a sweet aroma.
Transfer the sautéed onion and garlic to the slow cooker, then add the chopped carrots.
Pour in the vegetable broth, then stir in the rinsed lentils, tomato paste, cumin, smoked paprika, and chili flakes. Mix everything well to evenly distribute the spices and ingredients.
Cover the slow cooker and set it to low. Let it cook for 6 to 8 hours, or on high for 3 to 4 hours, until the lentils are tender and the stew has thickened to a hearty consistency.
Halfway through, give the stew a gentle stir to ensure even cooking and check the seasoning. Add salt if needed.
Once cooked, taste the stew and squeeze in fresh lemon juice to brighten the flavors. Adjust seasoning as desired.
Let the stew sit uncovered for about 10 minutes to allow the flavors to meld and the consistency to thicken slightly.
Serve hot, garnished with fresh herbs if desired, and enjoy the warm, comforting aroma and hearty texture of this slow-cooked lentil stew.
