Heat oven to 350°F. Cut small slit in center of broccoli and cheese sauce pouch. Microwave on High for 3 to 4 minutes, rotating pouch 1/4 turn once halfway through microwaving. Set aside to cool slightly.
Meanwhile, spray bottom only of 13x9-inch (3-quart) glass baking dish with cooking spray. Separate dough into 5 biscuits. Cut each biscuit into 8 pieces; arrange evenly in sprayed dish.
In large bowl, beat eggs, milk, mustard, salt and pepper with wire whisk until well blended. Stir in ham, onion, both cheeses, mushrooms and cooked broccoli and cheese sauce. Pour mixture over biscuit pieces in dish. Press down with back of spoon, making sure all biscuit pieces are covered with egg mixture.
Bake at 350°F. for 40 to 50 minutes or until edges are deep golden brown and center is set. Let stand 10 minutes before serving. Cut into squares.