Slice dark green scallion tops to equal 1/4 cup;
slice light green and white bottoms to equal 1/2
cup. Set aside, keeping scallion parts separate.
(Reserve the remaining scallions for another use.)
Toss together shrimp, lemon zest, and 1/2 teaspoon
of the kosher salt in a large bowl.
Heat oil in a large, deep skillet over medium. Add
garlic and scallion bottoms. Cook, stirring often,
until translucent, 3 minutes. Add orzo; cook,
stirring often, until lightly toasted, 2 minutes.
Stir in wine. Cook, stirring constantly, 1 minute.
Add stock and remaining 1 teaspoon salt; bring to
a simmer over medium-high.
Cover and reduce heat to low. Cook, undisturbed,
until orzo is tender, about 12 minutes, adding
shrimp during final 3 minutes of cook time. Remove
pan from heat. Sprinkle evenly with scallion tops,
parsley, and dill.