Place the chicken thighs in the bottom of the slow cooker. Add the rinsed lentils, diced onion, sliced carrots, minced garlic, and grated ginger on top.
Sprinkle the curry powder, cumin, and turmeric over the ingredients. Pour in the chicken broth and the can of diced tomatoes with their juices.
Season with salt and black pepper. Stir gently to combine everything except the chicken, which should stay at the bottom.
Cover and cook on low for 6 to 7 hours until the chicken is tender and the lentils are soft.
Remove the chicken thighs, shred them with two forks, and return the meat to the slow cooker. Stir to mix everything together.
Taste and adjust salt or pepper if needed. Ladle into bowls and top with chopped cilantro before serving.