Impossible Broccoli Pie
["2 pkg. (10 oz. each) frozen chopped broccoli", "3 c. shredded Cheddar cheese", "3/4 c. chopped onion", "1 1/3 c. milk", "3 eggs", "3/4 c. buttermilk baking mix", "3/4 tsp. salt", "1/4 tsp. pepper"]
["Grease 10-inch pie plate.", "Rinse broccoli under cold water to thaw.", "Drain thoroughly.", "Mix broccoli, 2 cups cheese and the onion in the pie plate.", "Beat milk, eggs, baking mix, salt and pepper until smooth.", "Pour into plate over broccoli.", "Bake at 400\u00b0 until a knife inserted in center comes out clean.", "Top with remaining cheese.", "Bake further until cheese melts.", "Let stand 5 minutes before serving."]
["broccoli", "Cheddar cheese", "onion", "milk", "eggs", "buttermilk baking mix", "salt", "pepper"]