Slice up mushrooms, onion and red pepper. Pour olive oil into a frying pan and turn to medium heat. Cook vegetables in frying pan until just beginning to soften. Turn off heat.
Melt margarine in a large sauce pan. Add Gluten Free Flour and stir to form a paste. Add almond milk and stir to combine. Measure in seasonings. Stir until thickens.
Transfer green bean mixture to a greased 9x13 inch pan and spread out evenly. Mix bread crumbs and crushed chips together in small bowl. Spread bread crumbs over beans in the pan.