Meanwhile, cut red peppers and cucumber into match-stick-thin slices; thinly slice green onions.
Set aside.
Cut chicken breast halves crosswise into 1-inch thick strips.
In a medium bowl combine cornstarch and salt.
Toss chicken strips in cornstarch mixture to coat.
In a 12-inch skillet over medium-high heat, in hot salad oil, cook chicken pieces, stirring quickly and constantly, until light browned and chicken losses its pink color throughout.
Remove chicken to a plate; keep warm.
To skillet over medium heat, add peanut butter, soy sauce, sesame oil, vinegar, sugar and 3/4 cup water; cook stirring constantly, until mixture is smooth.
Stir in linguine and heat though.
Spoon linguine mixture onto warm platter.
Top with red pepper and cucumber strips, then chicken strips and green onions.