1. Cook the macaroni in boiling salted water until al dente. Drain and place in a bowl.
2. Stir in the celery, spring onions, 1/2 the grated cheese, ham, parsley, Wattie's Bacon and Cheese Potato Bake Sauce, a dash of Lea & Perrins Worcestershire Sauce and milk. Season with pepper if wished.
3. Turn into an oven-proof dish and sprinkle over the remaining cheese and optional fresh breadcrumbs.
4. Bake at 190°C for 30-35 minutes until hot and golden.