Cook over medium low heat for about 10 minutes, turning the seafood halfway through. The shrimp should turn pink and opaque, and the tilapia should become white and flaky.
Prepare the Lemon Cream Sauce: In a small saucepan, whisk together the half and half, lemon juice, garlic powder, and paprika. Place the pan over medium heat and bring the mixture to a slow boil.
Once boiling, reduce the heat to low. Whisk in the Parmesan cheese, salt, and pepper. Stir the sauce frequently and continue to cook for an additional 10-15 minutes, or until it thickens to your desired consistency.