Whisk together honey, soy sauce, garlic, ginger, and red pepper flakes
Toss the shrimp with 3 tablespoons of the marinade and let sit for at least 15 minutes
Stir cornstarch into the remaining marinade and set aside
Pat the shrimp dry and discard excess marinade
Heat a large skillet over medium-high heat with oil
Cook the shrimp in a single layer until lightly browned, about 2 minutes per side
Add the reserved marinade with cornstarch and cook until thickened
Transfer to a serving dish, top with scallions, and serve
