Where's the Fudge????

I have not tried this recipe, but the person I got it from has a wonderful reputation for being a great candy maker.

In large heavy pan, mix:
4 1/2 C. sugar
1- 13 oz. can evaporated milk
Bring to a boil, reduce heat, but keep boiling. Stir constantly for 8 minutes then pour into a mixing bowl containing:

2- 12 oz. packages milk chocolate chips
1= 12 oz. package semi-sweet chocolate chips
2 squares butter (not margarine) cut up
Beat until smooth

Add 1 lb. package mini-marshmallows
Beat until smooth. Add nuts if desire.
Pour into a buttered 9x13 pan (I line the cake pan with buttered aluminum foil. When the fudge is set, I remove the foil from the cake pan and the fudge is easier to cut).
Refrigerate