Finely chop one-third of the onion; thinly slice remaining onion. In a large bowl, combine chopped onion, dried tomatoes, and 1 teaspoon of the Italian seasoning. Add ground beef, egg, bread crumbs, and salt; mix well. Shape into 12 meatballs. In a Dutch oven, brown meatballs in hot oil. Carefully drain off fat.

Meanwhile, cut off and discard upper stalks of fennel. If desired, save some of the feathery fennel leaves for a garnish. Remove any wilted outer layers; cut off a thin slice from fennel base. Cut fennel into thin wedges; add to Dutch oven with sliced onion, broth, garlic, the remaining 1 teaspoon Italian seasoning and the black pepper.

Bring to boiling; stir in orzo. Simmer, uncovered, for 10 to 15 minutes or until orzo is tender.

Stir in spinach. If desired, garnish soup with reserved fennel leaves. Makes 6 main-dish servings.

Prepare meatballs and fennel as above. After browning meatballs, place meatballs and sliced onion in a 5-quart slow cooker. Add fennel, broth, garlic, the remaining 1 teaspoon Italian seasoning, and the black pepper. Cover, cook on low-heat setting for 8 to 10 hours or on high-heat setting for 4 to 5 hours. If using low-heat setting, turn cooker to high-heat setting. Gently stir orzo into soup. Cover; cook 15 minutes more. Stir in spinach. Garnish as above.