Bring large pot of salted water to boil. Brush steaks all over with 1 1/2 tbsp. vinaigrette; season. Grill over medium-high, turning once, until browned, 10 minutes for medium-rare. Transfer to cutting board; let rest 10 minutes. Boil green beans, 3 minutes; drain. Transfer to bowl of ice water to chill; drain. Place in large bowl and toss with tomatoes, feta and 1 1/2 tbsp. vinaigrette; season. Serve with steak.