As with most shellfish, fresh shrimp should be cooked briefly to avoid a tough, rubbery texture. When grilling peeled and deveined shrimp, cook just until they turn pink and begin to curl -- only a few minutes.
If you don't have skewers, just cook shrimp in foil packet along with the rice mixture.
Use additional foil to make 4 smaller foil packets, filling each with 1/4 of the ingredients. This way each family member can customize their meal by adding or deleting ingredients as desired.