Heat a wok over high heat. Add oil and heat until hot. Add ginger, garlic, curry powder and mushrooms and stir-fry for 2 minutes or until light golden.
Add tomatoes and stir-fry 1-2 minutes until fragrant. Remove from the heat. Add yoghurt, stir until well coated. Reduce heat to medium. Return wok to the heat and cook 1-2 minutes or until heated through. Add spinach and cook 1 minute or until wilted.
Serve over basmati rice, topped with coriander.