Toss green beans and bell pepper strips with oil, salt, and pepper in a large bowl. Spread in a single layer on a baking sheet and roast 20-25 minutes or until vegetables are crisp tender and beginning to brown, stirring occasionally.
Bring the balsamic vinegar to a boil in a small saucepan over medium high heat. Simmer 5-7 minutes, or until vinegar is thick and syrupy, stirring occasionally.
Toss green bean mixutre with orange juice, lemon jucie, and orange zest in a large bowl. Season with salt and pepper, if desired.
Transfer to a serving dish, and drizzle with the balsamic vinegar syrup. Enjoy!