Place the yogurt, garam masala, turmeric and cumin in a bowl and mix well. Set aside.
Heat 1 tsp of the olive oil in a large frying pan over medium heat. Add the tofu and cook for 5-6 minutes until browned. Remove from the pan and set aside. Wipe the frying pan clean with kitchen towel.
Heat the remaining olive oil in the frying pan and sauté the onion, garlic and ginger for 5 minutes, or until the onion has softened. Add the spinach with a small splash of water and cook for 2-3 minutes, or until the spinach has wilted (you may have to add the spinach in batches if the pan isn’t big enough).
Return the tofu to the frying pan and warm through. Add the yogurt mixture a tablespoon at a time, stirring it through gently before adding the next tablespoon (this should prevent the yogurt from curdling).