In a pan, heat 1 tsp oil, sautee spinach until its mushy
Use a food processor or blender to blend soaked spinach, garlic, ginger, cashew nuts and Coconut milk into a puree and set aside.
Use the same pan, heat 2 tsp of oil, and cubed tofu. Sauté for 6-7 minutes till tofu is light brown and set aside. (I skip this step usually and it still tastes very good)
Now heat 1 tbsp of oil over medium heat. Once hot, add turmeric, mustard seeds, and cumin seeds one after the other and Sauté till they start to splutter.
Add onions and sauté until they are golden brown
Add in the prepared spinach puree and mix. Also, add 1/2 cup water and cook it for 10 mins until the raw taste of spinach is gone.
Add salt and cayenne to the puree and sauté for 3-4 minutes
Now, add the sautéed tofu to the spinach curry.
Cover and simmer the curry for 6 minutes on low heat.
Squeeze in fresh lemon juice and mix.