Pour sweetened condensed milk into a 2qt. microwave bowl. Add the chocolate chips. Microwave on high for 3 minutes. Remove from the microwave and stir until chocolat chips are melted. Stir in 1 teaspoon. vanilla. Add nuts and stir until mixed good.
Butter a 2qt. bowl(or line with foil) Pour fudge into bowl and refrigerate for 2 hours. It makes about 2 pounds. Cut into squares and keep in air tight container in refrigerator.
NOTE: When I use milk chocolate chips, I use 18 oz. You can use any flavors.