Marinated Artichoke and Green Bean Pasta Salad

Name: Marinated-Artichoke and Green-Bean Pasta Salad
Ingredients: 1 pound cavatappi or other short, corkscrew-shaped pasta; Kosher salt; 1 pound green beans, trimmed and cut into 2-inch pieces; 3 tablespoons extra-virgin olive oil; 2 jars (each 12 ounces) marinated artichoke hearts; 2 cups packed flat-leaf parsley leaves, chopped; Finely grated zest of 1 lemon, plus 2 tablespoons fresh juice; ½ cup thinly sliced red onion (from 1 small onion); ½ cup finely grated Parmesan; Red-pepper flakes, for serving