Put in 9x13 pan:

2 c. chopped walnuts
1/2 lb. butter (softened)
1 tsp. vanilla
18 oz. chocolate chips

In large saucepan, boil 7 minutes:

1 can Carnation evaporated milk
4 1/2 c. sugar

Pour into cake pan. Stir until melted. Refrigerate until set.