In a large pot of salted water, cook the pasta until just al dente. Drain and return to the pot. Cover to keep warm.
Meanwhile, in a large saute pan, heat the oil over medium-high heat. Add the pancetta and cook until golden brown, 3 to 4 minutes.
To the oil in the pan, add the onions and cook, stirring, for 2 minutes. Add the garlic and cook, stirring, for 30 seconds. Add the wine, 3/4 teaspoon salt, red pepper, lemon juice, and langoustines and cook, stirring, until the shellfish are pink and cooked through, about 5 minutes. Add the parsley and stir to combine.
Add the cooked pasta to the shellfish mixture and toss well to combine. Cook until the pasta is heated through, about 1 minute. Remove from the heat, add the lemon zest, and adjust the seasoning, to taste. Sprinkle with Parmesan. Spoon into individual pasta bowls or onto large plates, and serve immediately.
Recipe from Emeril Lagasse