Put a large pot of salted water on to boil.
Peel five 1-inch-wide strips of zest from the lemon with a peeler. Cut the lemon in half for juicing later.
Heat the oil in a large skillet over medium heat. Add the garlic and lemon strips and cook, shaking the pan occasionally, until the garlic starts to brown around the edges, about 3 minutes. Remove from the heat and use a fork to pick out and discard the lemon strips. Transfer a little more than 1/4 cup of the oil (without the garlic) to a small bowl.
Put the pasta in the water:
Raise the heat under the skillet to high and add the chile flakes and the clams. Cook the clams for 1 minute, shaking the pan. Pour in the wine and cook for 1 minute. Cover the pan and cook, shaking the pan occasionally, until all the clam shells open, 3 to 5 minutes.
Finish cooking the linguine until it’s just tender, about 10 minutes total. Drain and add to the clams. Raise the heat to high and cook for 1 to 2 minutes, tossing gently. Stir in the 1/2 cup parsley and a squeeze of lemon juice (about 1 Tbs.). Add more salt, pepper or lemon juice to taste. Serve immediatly, topped with a drizzle of the reserved lemon-garlic oil and more parsley.
nutrition information (per serving):