In a small saucepan over medium-low heat, heat the butter, garlic and cayenne.
Cook until the garlic is soft, about 3 minutes.
Add the wine, raise the heat to high, and cook until reduced by half.
Allow to cool.
Stir in 2 tbl.
of the parsley.
Pour the butter mixture over the shrimp.
Add the salt and toss everything to coat evenly.
Grill the shrimp over high heat (or you can cook in a skillet on the stove, but they are better on the grill), turning once, until just cooked and opaque, about 3-4 minutes total.
Meanwhile, cook the pasta al-dente.
Drain and toss with the olive oil, parmesan and remaining parsley.
Transfer the shrimp to a bowl and squeeze the lemon over them.
Toss.
To serve, put a bed of pasta on each plate and top with 4 large shrimp, and a sprig of parsley.