Pork Roast Roll

Peel and cube potatoes; boil in water with salt until tender. Drain, reserving liquid. Mash potatoes with cheese, nutmeg, egg white and 2 tablespoons reserved liquid. While this is cooking, butterfly roast 1" thick, leaving 1/2" from end. Open roast and pound with a mallet with waxed paper on top until meat is 1/2" thick. Drain and squeeze all liquid from spinach. Put spinach on top of meat, leaving 1/2" from seam edge in front. Next, smooth potato mixture on top of spinach. Roll meat up using toothpicks to hold togethe