In small bowl, combine all dressing ingredients; blend well. Set aside.
In large saucepan, bring 1 1/2 cups water to a boil. Add potatoes; return to a boil. Reduce heat; cover and cook 10 minutes. Add asparagus; cook 4 to 6 minutes or until potatoes and asparagus are crisp-tender. Drain; rinse with cold water to cool.
In large bowl, combine cooked potatoes, asparagus, onion and cheese. Add dressing; stir gently to coat. Cover; refrigerate at least 1 hour to blend flavors.