Place the lentils, coconut milk, lemongrass pieces, bell peppers, onion, garlic, ginger, curry paste, and vegetable broth into the slow cooker.
Stir everything together until the curry paste is mostly dissolved.
Cover and cook on low for 7 hours.
Remove and discard the lemongrass pieces.
Stir in the lime juice and add salt to taste.
Ladle into bowls and top with fresh cilantro before serving.