How to Make It
Cook pasta in a large pot of boiling salted water according to package instructions, adding edamame during the last 4 minutes of cooking.
Meanwhile, heat a small skillet over medium-high. Add lemon wedges, cut side down, and cook until well blistered, about 1 minute per side. Transfer to a plate.
Reserving 2 tablespoons of cooking liquid, drain pasta and edamame; transfer to a large bowl. Toss with 2 tablespoons oil; set aside until cool, 5 to 10 minutes.
Whisk together salt, vinegar, pepper, reserved cooking liquid, and remaining 4 tablespoons oil in a small bowl. Add to bowl with pasta and edamame along with arugula, feta, and walnuts; toss well. Squeeze seared lemon wedges over pasta.