In a large cast-iron skillet, heat 1 Tbsp oil over medium-high heat. Add tofu and cook, turning, until golden brown , about 7 minutes. Transfer to a plate and season with salt.
Heat remaining oil in a large pot over medium-high heat. Add onion and garlic and cook, stirring, until tender, about 5 minutes. Add ginger and spices and cook, stirring, until spices are toasted, about 1 minute. Add spinach and cook, stirring, until just wilted, 2 to 3 minutes.
Remove from heat and stir in yogurt. Season with salt and stir in golden tofu. Serve with rice.
Golden cubes of tofu, sauteed with mustard and coriander seed, replace paneer cheese in this nod to the classic Indian dish.