Chicken and Broccoli Pie

1 package frozen chopped broccoli    2 cups cheddar cheese shredded    1 1/2 cups cooked chicken cut up    2/3 cups onions chopped    1 1/3 cups milk    3 eggs    3/4 cups bisquick baking mix    3/4 teaspoons salt    1/4 teaspoons pepper

Heat oven to 400 degrees. Grease pie plate, 10x1 1/2 inches. Rinse broccoli under running cold water to thaw; drain thoroughly. Mix broccoli, 2 cups of cheese, the chicken and onion in plate. Beat milk, eggs, baking mix, salt and pepper until smooth, 15 seconds in blender on high or 1 minute with hand beater. Pour into plate. Bake until knife inserted in center comes out clean, 25 to 30 minutes. Top with remaining cheese. Bake just until cheese is melted, 1 to 2 minutes longer. Cool 5 minutes.