Reserve 2 tablespoons of the Marinade. Toss green beans, bell pepper, onion, carrots, and mushrooms with remaining Marinade in large bowl. Set aside.
Heat oil in cast iron skillet on grill over direct medium-high heat. Add cashews; cook and stir until toasted, about 30 to 45 seconds. Remove from skillet; set aside.
Stir vegetable mixture into skillet. Stir fry 4 to 5 minutes or until vegetables begin to char. Add reserved Marinade; stir fry 1 to 2 minutes or until vegetables are tender-crisp. Remove skillet from grill. Stir in toasted cashews.