Fantastic Fudge

500 gr chocolate (just slab chocolate from the supermarket will do: I like a mixture of milk and dark, but please yourself)
1 tin sweetened condensed milk
75 gr butter
1 teaspoon vanilla (or peppermint essence if you feel like a minty fudge)

Melt everything except the vanilla together over a low heat, do not boil. When the mixture is smooth and shiny, stir in the vanilla.
Pour into a dish lined with baking paper. I use a 20 x 25 cms oblong baking tin. See picture.
Cool and put in fridge to set. Cut into squares.
Sit back and wait for compliments.