Bring lentils and 4 cups of water to a boil in large pot or Dutch oven. Reduce heat to low, and simmer 15 minutes, or until lentils are firm-tender. Drain and transfer lentils to bowl.
Wipe out pot; heat oil over medium high. Sauté onion in oil 4 minutes, or until just golden.
Add carrots and rice, and cook 3 minutes, or until rice is toasted and fragrant, stirring constantly.
Add garlic, ginger and garam masala, and cook 1 minute more.
Stir in tomatoes, broth, salt, and lentils, and bring to a boil. Cover, reduce heat to low, and cook 20 minutes, or until liquid is mostly absorbed and rice is tender.
Season with salt and pepper to taste. Remove from heat, cover, and let stand 5 minutes.