Combine the rice and water in a small saucepan. Bring to a boil, reduce heat to low and cook until all the water is absorbed, about 15 minutes.
Meanwhile, heat the garlic oil in a skillet over medium heat; add the butter and melt. Pour in the wine and lemon juice and season with zest, salt, oregano and pepper; reduce heat to medium-low and simmer. Stir in the shrimp and cook until the shrimp turns pink, stirring regularly, 5 to 7 minutes. Sprinkle the parsley over the shrimp and cook another 2 minutes.
Combine the cornstarch and water and add to the shrimp mixture and stir until it thickens, about 1 minute more. Serve hot over the rice.