1Make the naan dough: mix flour, baking powder, and salt in a bowl. Add yogurt and water, stir until a shaggy dough forms. Knead for 2 minutes until smooth. Cover and set aside.
2Heat 1 tbsp ghee in a large pot over medium heat. Add cumin seeds and let them crackle for 30 seconds, then add diced onion and cook until soft, about 5 minutes.
3Stir in minced garlic, ginger, and sliced serrano chile. Cook for 1 minute until fragrant.
4Add turmeric, coriander, and garam masala. Stir constantly for 30 seconds.
5Pour in red lentils, diced tomato, coconut milk, and broth. Bring to a boil, then reduce to a simmer. Cook uncovered for 20–25 minutes, stirring occasionally, until lentils are tender and the dal is creamy. Season with salt and a squeeze of lime juice.
6While the dal cooks, divide naan dough into 4 equal balls. Let rest for 10 minutes, then roll each ball into a thin oval, about 0.25 inch thick.
7Heat a cast iron skillet over medium-high heat. Working in batches, cook each naan for 2–3 minutes per side until golden and puffed. Brush with melted butter.
8Ladle dal into bowls, drizzle with remaining ghee, garnish with fresh cilantro, and serve with warm naan.