It generally takes 3-5 minutes per side to grill sea scallops or shrimp. Scallop on the other hand can be tougher as they can't turn black while being cooked. The mystery lies in the texture of the scallop. Look to find good marks at grilling on both shrimp and scallions. Make sure to brush both sides with the reserved marinade. And they're juicy and tender! Let s sit here and enjoy these grilled scallions and shrimp kabobs! Use this recipe as a precooked roast.