This is a really quick recipe, but the longer you can marinate the shrimp the tastier it is. You can easily mix up the marinade in the morning leaving them to soak up the flavor for a few hours, then just cook them right before you want to serve them.
If shrimp are frozen, thaw in cool water. Leave the shell on and slice length wise to open and let drain in colander.
Mix parsley, garlic, lemon juice and olive oil in a small bowl. Add shrimp and stir to coat. Let marinade for at least 30 minutes but it can be several hours if doing ahead of time. If you'll marinade for over 30 minutes, put them in the refrigerator.
Heat a little olive oil in a sauté pan. Cook shrimp over medium heat for about 8 minutes, stirring often. Grind fresh black pepper over them while they cook. When they are almost done, pour over the white wine and let it cook down some. Place scampi on serving platter pouring over the wine sauce from the sauté pan and serve immediately.