Cook Orzo pasta according to package directions. Drain and set aside.

Meanwhile, add ground beef and diced onion to a large stock pot. Cook over medium heat until beef is browned and onion is tender.

While stirring, add chicken broth, beans, taco seasoning and diced tomatoes. Simmer on low until heated through, approximately 5-7 minutes.

Stir in cooked Orzo pasta.

Reduce heat to low and simmer for 5 minutes.

Remove from heat and serve in bowls. Top with sour cream and shredded cheese, if desired.