Foolproof Fudge

[2dogsmom]

2 sticks butter
4 cups sugar
1 cup milk
2 cups mini marshmallows
1 cup chopped nuts--if desired
12 oz package semi-sweet chocolate chips--i use nestle
13 oz chocolate bar--i use hersheys milk chocolate symphony

melt butter in a large saucepan. add sugar. add milk and marshmallows, stirring constantly. bring to a slight boil. remove from heat and add all chocolate. stir in nuts and pour into a greased 13 by 9-inch pan. refridgerate to cool.