Line a 9-inch cast iron skillet or pie dish with parchment and press in the bottom crust.
Sauté the onion in olive oil for 3 to 4 minutes, then add garlic and cook 30 seconds more.
Add the crumbled tofu, turmeric, nutritional yeast, oregano, salt, and pepper. Cook 3 to 4 minutes.
Stir in the spinach until wilted, about 2 minutes, then mix in the sun-dried tomatoes and plant milk. Cool 5 minutes.
Spread the filling evenly into the bottom crust.
Top with the second crust, trim and crimp the edges, and cut steam vents in the top.
Bake at 375°F for 35 to 40 minutes, until deeply golden.
Rest for at least 15 minutes before slicing.