Bring a large pot of salted water to a boil. Add the orzo and cook for 8 minutes.

While the orzo is cooking, combine the butter, lemon juice and zest, 1 teaspoon salt, pepper, and red pepper flakes in a large skillet and cook, stirring, over medium-high heat until the butter is melted. Add the shrimp and stir.

Using a slotted spoon, remove the orzo from the pasta water, drain off most of the pasta water, and add to the lemon butter sauce. Cook for another 2 – 3 minutes, stirring, or just until the shrimp are pink, and the orzo is tender.

Garnish with freshly grated Parmesan cheese and parsley.