Spray counter lightly with non-stick cooking spray. Roll dough into a 12x15-inch rectangle. Cover with plastic wrap and let rest.
Heat olive oil in a small skillet. Add onion, red pepper and mushrooms and saute until just tender.
Remove wrap from dough and spread with mustard, avoiding 1-inch around all edges. Layer middle third of dough, vertically, with ham, turkey and provolone cheese. Top with vegetable mixture and mozzarella cheese. Fold one third of dough over fillings. Repeat with remaining side.
Place seam side down on a large sprayed baking sheet. Tuck ends under and cut some vents in the top using a sharp knife. Brush with egg and sprinkle with sesame seeds. Cover with sprayed plastic wrap and let rise 30 minutes.
Remove wrap and bake at 350°F 25-30 minutes.