Melt butter in a medium nonstick skillet over medium heat; add celery and onion, and sauté 7 minutes or just until tender.
2
Stir together celery mixture, ground beef, 1 tablespoon Worcestershire sauce, breadcrumbs, and next 5 ingredients in a large bowl. Shape into a 10- x 5-inch loaf; place on a lightly greased broiler rack. Place rack in an aluminum foil-lined broiler pan.
3
Bake at 350° for 45 minutes. Stir together remaining 1 tablespoon Worcestershire sauce, tomato sauce, tomato paste, and 1 tablespoon ketchup until blended; pour evenly over meatloaf, and bake 10 to 15 more minutes or until no longer pink in center. Let stand 10 minutes before serving.