GREEN BEAN-MUSHROOM-BACON & CHEESE CASSEROLE

The traditional "green bean casserole" has always intrigued me. I see it mostly during the holidays and I want to enjoy it, although I'm not too fond of the mushroom soup sauce it usually has. This year, I set out to re-invent this holiday casserole and I absolutely love the final results.
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I used fresh green beans, sauteed sweet onions, portobello mushrooms, crisp bacon, a little cheddar cheese and my own white sauce. The resulting "green bean casserole" was delicious and we ate a ton of it. 1 pound of fresh green beans cut into 2" pieces
½ cup chopped sweet onion
½ pound of baby portobello mushrooms sliced
½ pound of bacon fried crisp (drained well & crumbled)
1 cup shredded cheddar cheese (loosely packed)
1 clove garlic minced finely
3 tablespoons white flour
1 teaspoon salt
scant ½ teaspoon black pepper
2½ cups milk
2 tablespoons butter

In a large frying pan, melt the butter and saute the chopped onions until they smell sweet; add the garlic and saute until it barely turns golden. Add the green beans and mushrooms (mixing well) and saute for a few minutes until they start to wilt just a little (don't cook them all the way through). Remove pan from heat and set aside.
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In a sauce pan, melt 3 tablespoons butter. When butter is hot, add (all at once) the flour, salt & pepper, stirring quickly. Cook on medium for about a minute (to remove any flour taste). Next, you are going to add the milk, a little at a time, whisking like a mad woman while you add the milk (this will eliminate lumps in the sauce). Once the milk and butter-flour mixture are mixed well, cook on medium heat (stirring every once in a while) until it gets nice and thick.

Remove from heat and stir in the cheese & crisp bacon. Add this mixture to the vegetables and stir well (but gently). Place in an lightly greased casserole dish and bake at 350 for about 30 minutes or until very hot.
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It was really tasty and the leftovers made a mouth watering lunch the next day.