Start thawing frozen turkey in fridge about 5 days prior to preparation. Remove giblets. Rinse thawed turkey inside and out. Dry with paper towels. Place breast side down in roasting pan.
In a large mixing bowl, combine flour + S + P + oil until you have consistency of a thin paste. Apply thin coat of paste to cover all of turkey's back. Let air dry x 30 minutes. Turn turkey over and apply an even coat all over turkey. Let dry.
Heat oven to 550 degrees. Bake turkey breast side up until crust is browned 20-30 minutes. Remove from oven and turn turkey onto its breast. Reset displaced crust on turkey's back. Bake until browned--another 20 minutes.
Add chopped veggies around turkey.
Carefully drizzle hot water onto browned crust and fill roasting pan 2/3 full. The water will remoisten the crust so it won't burn. The crust will keep turkey moist throughoutt baking. Turkey will be roasting immersed in water, creating the gravy.
Reduce oven temp to 350 degrees and bake 2-3 hours, depending on size.
When done, collect desired amt of gravy roux into a large sauce pan. Over low heat, add milk and/or water to desired gravy consistency to pour over turkey servings.