Chicken a la King

Chicken a la King
From: Mahna Mahna

2 tbsp butter
2 cups sliced fresh mushrooms
1/4 cup finely chopped green pepper
1/4 cup finely chopped red pepper
1 onion, finely chopped
2 tbsp flour
Salt & pepper to taste
1/2 cup chicken stock
2 cups milk
2 cups cubed leftover chicken
1/2 cup frozen peas

In a skillet, melt butter over medium-high heat. Add mushrooms, peppers and onion (some people might add some finely diced celery too, but I think they're crazy... celery is for pot pie, not a la king, you heathens!); cook for 5 minutes, or until onions are soft. Add flour and continue cooking, stirring often, for a minute or two (just enough to cook out the raw flour taste, but not enough to give it any colour). Season with S&P.
Whisk in chicken stock and milk. Bring to a boil, then reduce to a simmer and continue cooking, stirring often, until mixture thickens. Stir in chicken and frozen peas, and simmer until everything is heated through.
Serve piping hot on rice or fresh biscuits or in puff pastry shells, depending on how fancified you're feeling.