In a small bowl, whisk together chicken stock, tomato paste, curry powder, garam masala, turmeric, salt and pepper.
Place chicken, onion, garlic and ginger into a 4-qt slow cooker. Stir in chicken stock mixture.
Cover and cook on low heat for 4 hours. Stir in heavy cream, lime juice and brown sugar; season with salt and pepper, to taste.
Serve immediately with rice.
