In a bowl, toss together the shrimp, salt, pepper, and garlic powder.
Preheat a pan over medium heat, and add the oil.
Once the oil is hot, add the shrimp, and sear until all sides are colored, about 30 seconds per side. Immediately remove from heat, and set the shrimp aside on a plate.
To the same pan, add the lemon slices, and cook over medium heat until seared on both sides, about 30 seconds. Set lemon aside with the shrimp.
To the same pan, add the onion and minced garlic. Cook over medium heat, stirring occasionally, until fragrant, about 2 minutes. Stir in the oregano.
Add the orzo, and toast in the pan, stirring often, for about 3 minutes, or until the orzo turns slightly darker in color.
Deglaze the pan by adding the wine to the pan and cooking over medium heat, stirring occasionally, until the orzo soaks up the wine. Immediately add the chicken broth.
Bring the broth to a simmer, and reduce the heat to low. Cook, uncovered, stirring occasionally, for about 10 minutes, or until the orzo has absorbed 90% of the broth.
Return the shrimp and lemon to the pan, and cook until warmed through, about 2 minutes. Season to taste with additional salt and pepper. Serve with fresh basil.
