- Heat 2 tablespoons oil or ghee in a wok or large pan over medium heat. Add sliced onions and chopped ginger, sauté until onions turn golden brown. 
- Add turmeric powder, chile powder, and salt to the pan. Sauté for 2 minutes, stirring constantly to prevent burning. 
- Add chopped mushrooms, potatoes, and sliced tomatoes to the pan. Cook over gentle heat until potatoes are tender, adding a splash of water if needed to prevent sticking. 
- While the curry cooks, prepare the tempering: heat 2 tablespoons oil in a small skillet over medium heat. Add mustard seeds and fry until they begin to pop. 
- Add curry leaves, sliced garlic, and shredded coconut to the tempering oil. Stir and fry until coconut turns golden. Remove from heat immediately. 
- Once potatoes are tender, stir sliced spinach into the curry and cook until wilted. 
- Add garam masala, chopped cilantro, and lemon juice to the curry, stirring well to combine. 
- Pour the tempering mixture over the curry and serve hot with dal and rice.