Melt 1 1/2 cups chocolate chips (I like semi sweet), with 3/4 cup sweetened condensed milk (14 oz can) over low heat. Once chips melted, place in a 8 x 8 pan (I lined my pan with parchment paper, that I lightly sprayed). Place in refrigerator for about 10 minutes.
Then melt the white chips, with the remaining sweetened condensed milk. Once chips are melted, remove from heat; add food coloring and peppermint extract. Then layer over chocolate and place back in refrigerator for about 15 minutes.
Then melt the remaining chocolate chips (a cup) with the shortening in 30 second intervals in the microwave until chips are melted. Then layer over the green mint layer. Then top with the Andes mints. Put in refrigerator for 3-4 hours. Then cut into squares and store in sealed container.