Clean the langoustines by washing them under cold water and then peel. To peel, start with blanching langoustines by cooking for 20 seconds in boiling water and then immediately transferring to an ice bath. This will make the outer shell pliable and easier to remove,
Mix together toasted walnuts, parsley, the zest from the lemon and 1 of the grated garlic cloves. Season with salt and pepper and set aside.
Bring a large pot of salted water to a boil. Add pasta and cook very al dente, about 3 minutes short of the suggested cooking time on the box.
While the pasta cooks, heat oil in a skillet. Add chorizo and cook until just barely browned. Add remaining garlic, wine and langoustines. Cover to steam the langoustines for 3-5 minutes.
Drain and pasta and reserve about 2 cups of the cooking liquid. Add pasta and 1 cup of pasta water to skillet with langoustines and chorizo. Cook over medium-heat until sauce begins to thicken, about 5 minutes. Top with walnut mixture. Serve with lemon wedges.
