To assemble: With a short end of a lavash facing you, spread about 2 slightly rounded teaspoons of the mustard over the entire lavash. Cover with a quarter of the pastrami, followed by the Swiss cheese and a quarter of the coleslaw, and roll the wrap away from you. Complete the wraps with the remaining ingredients. Or, if you prefer, prepare all at once, assembly-line style. Cut in half on the bias.