In a large microwaveable bowl, melt the cream cheese in 30 second intervals, stirring after every 30 seconds. Add the drained chicken, 1 cup shredded cheese, and the rest of the ingredients, and mix well.
Transfer to a microwaveable serving bowl or dish. Microwave for 5 minutes, stirring gently halfway through. Top with the remaining 1/4 cup shredded cheddar cheese and microwave for another 30 seconds, or until the cheese is melted. Serve warm with your favorite dipping chips or veggies.