Heat oven to 375 degrees. Spray cookie sheet with nonstick cooking spray.
In a large bowl combine ham, broccoli, cheese, mushrooms, mayonnaise, and mustard, mix well.
Unroll both cans of dough into 2 large rectangles. Place dough with long sides together on sprayed cookie sheet, forming 15x12 inch rectangle. Press edges and perferations together and seal.
Spoon and spread ham mixture lengthwise in 6-inch wide strip down center of dough. With scissors or sharp knife, make cuts 1 1/2 inches apart on long sides of dough to within 1/2 inch of filling. Twisting each strip once, alternately cross strips over filling. Tuck short ends under, press to seal. Brush dough with beaten egg white.
Bake 375 degrees for 28-33 minutes or until deep golden brown. Cool 5 minutes. Cut crosswise into slices.