Heat oven to 350. Grease a 13x9x2" baking dish. Layer beef, onion, celery, tomatoes and cheese in dish. Beat remaining ingred. til smooth, 15 sec. in blender on high or 1 min. with electric mixer on high. Pour into dish. Bake until knife inserted in center comes out clean, 40-50 minutes. Cool 5 minutes. Garnish with parsley sprigs if desired. Serves: 8-10. High Alt.Bake 70-75 minutes.