Summarize the following:
Peel the banana and cut it into 2-inch (5-cm) chunks. Place these frozen banana chunks in your freezer for 20 to 30 minutes, or until they become frozen solid.  You should tray freeze the bananas to prevent them from sticking together. Cover a small cookie sheet with parchment paper and arrange the banana chunks on the sheet in a single layer. Do not let the pieces touch. Stick the cookie sheet in the freezer. Done in this manner, the banana pieces should freeze separately, making them easier to blend into the shake. Add the vanilla coconut milk ice cream, frozen banana chunks, 1/4 cup (60 ml) cacao nibs, peppermint oil, almond milk, spinach, and avocado to the blender. Blend on high speed until smooth and evenly colored.  This should take anywhere from 30 seconds to 2 minutes, depending on the speed and strength of your blender. The coconut milk ice cream and almond milk remove dairy from the equation. The spinach and avocado give the shamrock shake a great green color without the use of dyes. The cacao nibs add a hint of milk chocolate flavor, which complements the taste of mint. Pour your shake into serving glasses and serve immediately. If desired, sprinkle each shake with additional cacao nibs before serving for an added boost of chocolate flavor.

Summary:
Freeze the banana. Blend all the ingredients together. Transfer into serving glasses and sprinkle with cacao nibs.