Rinse lentils and place them in a 6-quart slow cooker. Add the onion, garlic, ginger, curry paste, garam masala, bay leaves, turmeric, cumin, salt, and cayenne. Stir to combine thoroughly.
Add the canned tomatoes, tomato paste, broth, and cauliflower. Stir well to combine, making sure the lentils are mostly submerged. Cover and cook on high for 3 1/2 hours.
Stir in the carrot rice and cook together until the lentils and rice are soft but not mushy, about 30 minutes more.
Remove the bay leaves. Serve the mixture over rice, if desired, and top with cashew raita and cilantro sprigs.
Notes
Leftover curry will keep in an airtight container in the fridge for up to 5 days and can be frozen for up to 4 weeks.