Pat the tofu dry and wrap in a few layers of clean paper towels. Place the tofu between two dinner plates and weight the top with something heavy (I use a can of tomatoes).
Let sit for 10 minutes to press out the excess liquid.
Place the pressed tofu in a small bowl and mash up with a fork.
Heat the oil in a large skillet over medium heat. Add the onion and cook until softened, 4 to 5 minutes.
Add the tofu, turmeric, garlic powder, salt, and pepper, and cook until fragrant, about 1 minute.
Fold in 1/4 cup pesto and spinach, and cook until spinach has just wilted. Taste and season with additional pesto, salt, or pepper. Enjoy warm with tortillas or toast.