In a large saucepan, melt one stick of butter; saute the onion and bell pepper. Add in the mushroom soup. Cook on medium heat for 10 minutes.
In a large glass bowl, combine 1 stick of butter, milk, flour and salt. Microwave for 2 minutes. Remove and stir. Microwave again for 2 more minutes then add cheese. Let the cheese melt and then stir the mixture.
In the large saucepan, combine both of the mixtures together and add the crawfish. Cook on medium to low heat for 20 minutes. Add the noodles. Mix together and serve.
