Step 1

In a 6-qt. stockpot, cook pasta according to package directions; drain and return to pot.

Step 2

Meanwhile, in a large skillet, heat 2 tablespoons oil over medium-high heat; sear scallops in batches until opaque and edges are golden brown, about 2 minutes per side. Remove from skillet; keep warm.

Step 3

In same skillet, saute radishes, garlic and pepper flakes in remaining 1 tablespoon oil until radishes are tender, 2-3 minutes. Stir in green onions and salt; cook 1 minute longer. Add to pasta; toss to combine. Sprinkle with lemon zest and juice. Top with scallops to serve.