To a medium pot, add the butter over medium heat. When the butter starts to get hot, add the poblano & serrano pepper, onion and garlic. Saute for 1 to 2 minutes to soften. Then add the tomato and saute for 1 more minute.
Add the milk and salt and mix. When the milk starts to bubble, start adding the cheese a little bit at the time ensuring it melts first prior to adding the rest of the cheese. Keep stirring to avoid burning the mixture at the bottom.
Add the ground chipotle if using any. Mix to combine all ingredients.