Bring a pot of salted water to a boil and cook the orzo according to package directions until just al dente, about 8 to 9 minutes. Drain and set aside.

Pat chicken breasts dry and season with onion powder, garlic powder, paprika, salt, and pepper. Cook in olive oil over medium-high heat for 5 to 6 minutes per side until golden and cooked through to an internal temperature of 165 degrees F. Rest for 5 minutes, then dice into bite-sized pieces.

In a large skillet or Dutch oven, melt butter with olive oil over medium-high heat. Add the diced onion, carrots, and celery. Saute for 4 to 5 minutes, stirring often, until softened and fragrant.

Reduce heat to low. Sprinkle flour evenly over the cooked vegetables and stir constantly for 2 to 3 minutes until a thick paste forms.

Slowly pour in chicken broth while whisking, followed by the heavy cream. Whisk until completely smooth and the sauce begins to thicken, about 3 to 4 minutes.

Stir in chicken bouillon powder and diced cooked chicken. Simmer gently for 3 to 4 minutes until the sauce coats the back of a spoon. Fold in the drained orzo, stir to combine, and heat through for 2 minutes.

Spoon into bowls and serve immediately. Garnish with chopped fresh parsley or cracked black pepper if desired.