Heat oil in large nonstick skillet over medium-high heat. Add onion; saute 2 minutes. Add broccoli, squash, red pepper, green beans and 1/2 cup sauce; cook 3 to 5 minutes. Add arugula and bok choy; stir until wilted. Add remaining sauce. Bring to boiling; cover and cook until beans and broccoli are tender, about 7 minutes.