Key Lime Pie (In a jar!)

I've really been craving some key lime pie for the last couple of days. Rather than whip up (& eat!) a whole pie I thought I’d create a recipe for one. The great thing about making it in an old jar is that you can take it anywhere with you (just remember to keep the lid). The green colour in this comes from avocados - in fact this is a great recipe to use up any overripe avocados you may have.