In a large bowl combine flour and salt. Cut in shortening until mixture resembles coarse crumbs. Gradually add the water and mix until a ball is formed. Divide dough into two, one for the bottom and one for the top of the pie.

Press one of the balls of dough into the bottom of a pie dish, rising up the sides slightly OR you can roll out the bottom crust and set into the pie dish. Roll the other ball of dough out flat into a large circle to cover the pie once you put the filling in.

Preheat your oven to 180 C.

In a large skillet, saute onions and mushrooms until onions start to become a little translucent. Add the meat and cook thoroughly. Drain the drippings and stir in garlic powder, oregano, salt, and pepper. Remove from heat and let cool slightly.

In a separate bowl, beat eggs, milk, and mayo together. Combine with the meat mixture. Fold in cheeses and pour mixture into the prepared pie dish.

Cover pie with second portion of pie crust and seal off around the edges. Bake for 15 minutes, then reduce heat to 150 C and bake for 20-30 minutes more, or until an inserted knife comes out clean. Let stand about ten minutes before cutting. Serve. Toast or fresh hash browns would be great side dishes here.