Spray large non-stick skillet with cooking spray. Heat skillet medium over medium heat. Add onion and green pepper; cook, stirring frequently, until softened, about 5 minutes. Add ham.
Whisk eggs and hot pepper sauce in small bowl. Pour into skillet. As mixture begins to set, gently move spatula across bottom and side of skillet to form large, soft curds. Cook until eggs are thickened and no visible liquid egg remains.
Spread 1 tsp (5 mL) mustard inside each pita half. Line pitas with lettuce. Divide scrambled eggs and cheese between pitas.