Turn up the flame and add the shrimp. Toss for a minute or two, seasoning with salt and pepper as you go.
Add the white wine. Let simmer for just another few minutes more, until the shrimp turns pink and loses its translucence. The exact cooking time will depend on the size of the shrimp.
Remove the shrimp to a serving dish. Add the lemon juice, parsley and freshly ground black pepper (and red pepper flakes if using) to the sauce remaining in the skillet and simmer for another minute or so.
Nap the shrimp with the sauce and serve immediately, topped with more parsley and a few red pepper flakes if you like, with lots of crusty bread on the side for dipping.
Notes
Total cooking times will vary according to the size of your shrimp. As a general rule of thumb, jumbo shrimp take about 7 to 8 minutes to cooking, large shrimp about 5 to 7 minutes, and medium sized shrimp only 3 to 4 minutes.