1. Cook pasta in a medium pot of boiling salted water until al dente, according to package instructions. Reserve 1/4 cup pasta water; add peas to pasta, and drain. Return pasta and peas to pot. Add lemon juice, parsley, and 1/2 tablespoon butter. Toss, adding reserved pasta water a little at a time to create a thin sauce that coats pappardelle. Season with salt and pepper.

2. Pat scallops dry with a paper towel; season with salt and pepper. In a small skillet, heat remaining 1/2 tablespoon butter over medium. Cook scallops until browned on one side, 2 to 3 minutes. Flip; cook until opaque throughout, 30 to 60 seconds more. Serve with pasta.