Dough: Mix 1st three ingredients and let sit 10 minutes. Add remaining ingredients and knead a few times just till smooth.
Place in a greased bowl and set aside while you prepare the filling.
Roll or pat dough out on a large cookie sheet or jelly roll pan that has been greased.
Combine the mayonnaise and mustard and spread evenly over the dough.
Cut 1 inch strips along both of the long sides of the rectangle, leaving a 3-4" strip down the middle.
Combine the remaining filling ingredients, then place on the center strip of dough. Fold the 1" strips over the filling, alternating from side to side. It's fine if some of the filling is showing.
Bake at 350° for 25-30 minutes, or till golden brown.