Cook the orzo pasta in a large pot of salted boiling water (according to package directions) for 9-11 minutes or until al dente. Drain, rinse under cool water and set aside.

Preheat a large (12-inch) skillet over medium-high heat, add the olive oil and chicken. Season the chicken with salt and pepper. Cook the chicken for 7-9 minutes or until lightly golden and no longer pink in the center. Remove the chicken from the skillet, place onto a clean plate and set aside.

Turn down the temperature of the burner to medium low, add the butter, onions, and garlic. Cook for 1-2 minutes or just until tender and fragrant.

Add the chicken broth, dried mustard, sweet paprika, and ground thyme to the onions. Stir together and cook for an additional 2-3 minutes or just until the broth starts to simmer.

Add the cheddar cheese soup and whole milk, stirring until the sauce is smooth.

Stir in the reserved orzo pasta until fully coated in the cheese sauce. Add the chicken and spinach, stirring just until combined. Let it cook for an additional 2-3 minutes or just until the spinach has completely wilted into the cheese sauce.

Remove from the heat and serve immediately with a light garnish of parsley if desired.