Green Bean Casserole - An American classic

I was introduced to Green bean casserole by Jana, my room mate in Phoenix. She would cook vegetarian versions of dishes using soy burgers instead of meat for me to try. She has made vegetarian chili and vegetarian spaghetti and meat balls just for me. She used to add extra Jalapenos in my batch to spice things up. She introduced me to Mac n cheese, baked beans, quiche, grilled cheese sandwich, black licorice, blue cheese and many more... Looks like I am becoming nostalgic here... She used Campbell's mushroom soup in her recipe, but I made white sauce and sauteed mushrooms separately.

Green beans - about 1 1/2 pounds
Mushroom - 8 oz (I used the brown crimini variety)
Celery stalks - 3 to 4 diced
Onion - 1 large diced
Butter - 2 tsp
Salt, red chilli flakes, ground black pepper to taste
Cheese as much as desired (I used pepper jack) - grated

For white sauce:
butter - 1 1/2 tbsp
flour - 1 1/2 tbsp
milk - 1 1/2 cup

To prepare white sauce, melt butter in a sauce pan over low heat. Add flour and fry till very light brown. Add milk slowly and mix well without lumps. Keep stirring and remove sauce from heat when the mixture starts to boil. (can be removed when you see the first bubble). Add salt, pepper and red chilli flakes (for the entire dish) to the sauce and set aside.

Wash and cut green beans into 1 1/2 to 2 inch long pieces. Microwave green beans with few sprinkles of water about 7 - 10 minutes (or until half cooked) and set aside. I learnt from "Food Network" that mushrooms become leathery in texture when washed and it is enough if they are wiped with wet cloth or paper towel. Clean and slice mushrooms. Heat 2 tsp of butter over medium heat and saute onions for about a minute. You can add very little salt now to bring out the sweetness of the onion. Add mushrooms and saute for another 30 seconds. Add celery stacks and saute for 30 more seconds and remove from heat. Add the microwaved green beans and mix. Remove the vegetables to a oven proof casserole dish. (My casserole is stove top safe too, so I used the same for sauteing and baking. One less dish to wash :-) ) Add white sauce and toss in. Top off with grated cheese and bake covered in the oven at 400F for about 30 -35 minutes (until cheese melts completely and the mixtures bubbles over). Remove the cover and broil for 3-4 minutes for the cheese to brown slightly. Remove from oven. I sprinkled some French fried onions (out of the can - available in most grocery stores) for a little crunch. Tasty GBC (as I call it) is ready to serve.