Pre heat oven 350° to toast walnuts and pecans, spread evenly on a baking sheet or in a shallow pan. Bake stirring once or twice until lightly browned and fragrant. 7to12 min coarsely chop and set aside

Line 9in square cake pan with parchment or wax paper; set aside.

Mix: in large heavy saucepan combine both the chocolates and sweetened condensed milk. Warm through over low heat, stirring until chocolate is melted and the mixture is smooth. Remove from the heat and stir in the vanilla, salt and 2cups of walnuts and pecans. Pour into the prepared pan and smooth the top sprinkle the top with the remaining 1cup of walnuts and pecans and press gently to secure them in the fudge. Cover loosely with plastic wrap and refrigerate until set; about 2hrs or overnight

To serve: turn out the fudge onto a cutting board; remove the lining paper. Flip the fudge cut into 1-inch squares. Store in an airtight container. In the refrigerator for up to 5 days.