In a large skillet over medium-high heat, sauté the chicken breast in the olive oil until almost completely cooked.
Reduce the heat to medium and add the onion, green pepper, garlic, salt, and pepper into the skillet with the chicken and cook for approximately 4-5 minutes, stirring occasionally.
Stir the mushrooms and Worcestershire sauce into the skillet and allow to cook for 2-3 more minutes.
Meanwhile, add the onion soup mix and the beef broth to the cooked orzo pasta and stir well to combine thoroughly.
Add the chicken and mushroom mixture to the orzo pasta and stir well to combine.
Prepare a 2-quart casserole dish by spraying with nonstick cooking spray and add the chicken orzo mixture into the casserole dish.
Evenly sprinkle the top with Parmesan cheese.
Bake in a preheated oven for 15 minutes or until the Parmesan cheese is golden brown.
Notes
If preparing in advance, refrigerate the unbaked pasta after adding it to the casserole dish. Cover and refrigerate for up to 2 days.When ready to bake, allow the casserole to sit at room temperature for at least 45 minutes before baking. Bake as called for in the recipe.