1. Thaw dough until firm, yet easy to roll. Roll out each dough in package to a large rectangle.
2. Sauté onions in a bit of oil; shut off ﬂame. Add sauerkraut, mayonnaise, mustard, and pastrami; mix well. Divide mixture in half.
3. Spread each portion of mixture onto one dough rectangle and roll up jelly roll style. (You can also mound mixture in a line down the center of dough and close up, knish style.)
4. Place, seam-side down, on cookie sheet and brush with beaten egg. Bake at 350 degrees Fahrenheit for one hour. Let cool slightly before cutting.
While the deli roll is still raw, wrap in foil and freeze. When you’re ready to use it, unwrap the foil, place on a cookie sheet, glaze, and bake!