Heat a large skillet over medium heat and add the butter. Once melted, add the sliced onions and poblano peppers and saute for about 30-40 minutes until golden brown and caramelized. Let cool when done.
Preheat the oven to 425 degrees Fahrenheit.
In a large mixing bowl, mix together the cream cheese, sour cream, corn, caramelized onions, and a pinch of salt and pepper.
Pour into a baking dish and place into the oven to bake for 25-30 minutes or until the edges are bubbly.
Garnish with chives if desired and serve with the crackers!