Melt: In saucepan over low heat, melt marshmallows with sweetened condensed milk and salt. Add chips & stir until melted.

Cool: Remove from heat; stir in nuts & vanilla. Spread evenly into wax paper -lined square pan (9x9, usually). Chill 2 hours or until firm. Turn fudge onto cutting board; peel off paper & cut into squares. Store loosely covered at room temperature.