In 12-inch nonstick skillet, heat oil over medium-high heat. Add sausage and onion; cook 2 minutes, stirring occasionally.
Stir in broth and water. Heat to boiling. Stir in orzo; boil 2 minutes. Add asparagus and pimientos. Reduce heat to medium. Cover; return to boiling. Cook 8 to 10 minutes or until pasta is tender.