Heat olive oil in a large skillet over medium heat. Once hot, add the chopped onion and diced bell pepper. Sauté for about 4-5 minutes until the vegetables are softened.
Add the minced garlic to the skillet and cook for another 1-2 minutes until fragrant.
Stir in the orzo pasta and toast it by cooking for about 2 minutes, continuously stirring to avoid burning.
Pour in the chicken broth and bring the mixture to a boil. Lower the heat, cover the skillet, and let it simmer for about 10 minutes until the orzo is tender and has absorbed most of the liquid. Stir occasionally.
Add the shrimp to the skillet along with the lemon zest, lemon juice, dried oregano, salt, and pepper. Cook for an additional 3-5 minutes or until the shrimp turn pink and are cooked through.
Remove the skillet from heat and let it sit uncovered for a couple of minutes to allow the flavors to meld.
Garnish with fresh parsley and serve with lemon slices on the side.