Rinse red lentils under cold running water. Place them in a large pan. Cover with enough water (I used around 3 cups of water) and place the pan over medium-high heat. Cover with lid, and simmer until lentils are well-cooked.
Add kale, cauliflower and enough salt. Stir in ground turmeric, red chili powder and garlic. Bring to a boil. Reduce heat, and cover with a lid. Cook until the vegetables are tender. Add more water if needed. Remove from heat. Set aside.
To make the tempered spices, heat oil in a small frying pan over medium-high heat. Splutter cumin seeds. Add red onion (or shallots), dried red chilies and curry leaves. Saute, stirring, for 2-3 minutes, or until onions turn golden brown. Remove from heat.
Add tempered spices to the lentil curry. Mix well. Serve warm with rice or roti.
Notes
You can use your favorite lentils in this recipe. I used red lentils (or masoor dal) as they cook really quickly.