Fit pie crust into a 9-inch pie pan and crimp the edges. Use a fork to pierce holes in the bottom. Press a double layer of aluminum foil into the pie crust. Bake for 8 minutes. Remove foil.
In a large bowl, whisk together mayonnaise, milk, flour, seafood seasoning, salt, pepper and eggs.
Add swiss cheese, cheddar cheese, crab meat, and green onions and gently stir in.
Transfer filling to pie crust. Bake for 30 to 35 minutes.
Notes
Add a pinch of cayenne pepper to the filling to make it a little spicy.