Stir cream cheese and mayo together in a medium bowl until smooth. Stir in drained chiles and peppers. Pour mixture into a microwave safe serving dish. Top with Parmesan cheese.
Microwave on high until hot and bubbly, approx 3 to 5 minutes- checking every minute. Once it starts to brown slightly around the edges remove it from microwave and place it under the broiler briefly to complete the browning. Be sure to watch carefully, so it doesn't burn. Serve with toasted baguette slices.