Heat the frozen spinach according to package instructions. Press it firmly through a colander to remove as much moisture as you can. Set the spinach aside.
Place the tofu, nutritional yeast, salt, garlic and onion powder, and lemon juice in a blender and blend till smooth.
Heat the oil over medium in a large skillet. Add the shallots and sauté for 5 minutes, stirring often, or until they're gently browning. Add the spinach and the blended tofu mixture. Heat, stirring as you go, until the ingredients are mixed and warm through. Taste and add extra salt and/or freshly ground pepper to taste. Serve hot.
*You can substitute a few tablespoons of vegetable broth if you wish.