Preheat oven to 350°

Sautee onions in butter in large skillet over medium heat, until soft

Stir in flour until smooth

Stir in salt, sugar, and sour cream

Add green beans, stir to coat

Transfer mix to 2 1/2 qt. casserole dish

In separate bowl mix together crushed ritz crackers, French fried onions and melted butter

Cover green bean mixture with cheddar cheese, then cracker mixture

Bake for 30 mins. or until the top is golden brown and the cheese is bubbly

If you really miss the cream of mushroom soup, you could always add some into the sour cream mixture. Just reduce the sour cream to half and add cream of mushroom soup. You could also add in fresh mushrooms with your onions :-)**