Prepare pie crusts. If you are using store-bought, remove crusts from packaging and let thaw for at least 1 hour before using. This will make the dough more moldable when it's time to top the pot pies. Follow these instructions for a homemade pie crust. Once your pie crust is ready, divide into half and roll out each half onto a piece of floured parchment paper until your dough is about ⅛" thick and you have two circles about 12" across. Place the top crust in the refrigerator to chill. Placing your hand underneath the parchment paper, gently flip one of the pie crusts into the pie pan. Peel off the parchment paper and press the crust evenly into the pie pan, trimming any edges that hang over. Place in the refrigerator while making the filling.
Preheat the oven to 375F.
Pat the tofu dry and cut it into ½″ cubes. Add 1 tablespoon of oil to a large skillet (at least 10") over medium-high heat. Test the hotness of the oil by adding a couple of drops of water to the pan. It should immediately sizzle. Add the tofu and sauté for about 5 minutes, stirring often, until the tofu is brown on all sides. Remove from heat and set aside.
Clean out the skillet and return to heat. Add the remaining oil. Once hot, add onions to the skillet. Sauté for 5 minutes until translucent and fragrant. Add potatoes, peas, carrots, and mushrooms and sauté for another 3-4 minutes to thaw the peas and carrots.
Stir in flour to lightly coat the vegetables. Once the vegetables are fully coated, add vegetable broth, milk, spices, and herbs. Bring to a light simmer and simmer for 20-25 minutes, uncovered, until potatoes are tender and sauce is slightly thickened. Stir in the tofu.
Pour the filling into the chilled pie crust, mounding the top. Top with the 2nd pie crust and seal around the edges with your fingers. Brush the top crust with non-dairy milk or a chickpea flour egg to give the pie crust a golden shine. Cut 2 (1″) slits in the tops of each pot pie and bake 35-40 minutes until lightly browned and liquid is bubbling from the tops. Remove from the oven and let cool 10 minutes before serving.