King Ranch Chicken Casserole

1 large onion, chopped
1 large red pepper, finely chopped
1 large poblano pepper, finely chopped
1 jalapeno pepper, finely chopped
1 1/2 tbsp. garlic, minced
3 tbsp. flour 
1 cup chicken broth
2 cups milk
1 can Rotel tomatoes and green chiles
Salt and pepper
1 tsp. chile powder
2 cups crushed tortilla chips (I think I used more)
2 cups shredded chicken, cooked
2 cups (6 oz) colby jack or pepper jack cheese

Heat pan with cooking spray and saute onion, red pepper, poblano and jalapeno.  Cook until tender for about 6 - 8 minutes.  Add garlic and cook for about 2 minutes. 

Whisk in flour and cook for another minute, continue whisking and slowly add broth, then milk.  Heat to almost boiling while whisking, then cook for about 3 - 4 minutes or until thickened.  Stir in tomatoes, salt, pepper and chile powder.  Remove from heat.  

Spread thin, even layer on bottom of prepared dish.  Top with half the chips, sauce, chicken and cheese, then repeat.  Bake 30 minutes or until bubbly.  Allow to set for 5 minutes before serving.