Combine first 4 ingredients, 2 teaspoons lemon zest, and 1/2 teaspoons rosemary in a medium bowl. Shape into 30 (1-inch) meatballs (about 1 level tablespoons each).
Saute meatballs, in two batches, in 1 tablespoons hot oil per batch in a dutch oven over medium heat 3-4 minutes or until browned. Remove with a slotted spoon.
Saute onion and next 2 ingredients in remaining 1 tablespoons hot oil in dutch oven over medium-high heat 3-5 minutes or until tender. Stir in broth, lemon juice,and remaining 2 teaspoons zest and 1/2 teaspoons rosemary. Bring to a boil, stirring occasionally. Add orzo. Reduce heat to medium; simmer, stirring occasionally, 7 - 9 minutes or until pasta is almost tender.
Stir in meatballs; simmer, stirring occasionally, 5-7 minutes or until meatballs are thoroughly cooked. Add salt and pepper to taste. Top with cheese and parsley.