Toss the spinach into a large pot of boiling salt water and blanch for 1 minute.
Dump the spinach into a colander and press firmly with the back of a spoon to extract as much water as possible. Use a knife to chop the spinach some. Set aside.
Fry the cubed tofu for a few minutes until light brown on all sides, gently turning to avoid breaking up the cubes. Remove the tofu from the skillet and set aside.
Sauté the onions, garlic, and ginger. Cook and stir for about 5 minutes until soft.
Mix all the spices in a small bowl then sprinkle them into the onion mixture; continue to stir to marry the flavors, about 1 minute.
Fold in the chopped spinach and give everything a good toss.
Shut off the heat and stir the sour cream and yogurt into the spinach to incorporate. The mixture should be creamy and somewhat thick.
Gently fold in the fried tofu cubes, season with salt, to taste, and serve with steamed basmati rice and/or flat bread.