Melt butter in water and then bring to rapid boil. Add the flour quickly and remove from heat, beating in the flour until the mixture leaves the sides of the pan. Spread onto a plate to cool quickly and clean the saucepan. Add the mixture back into the pan once body temp and beat in the eggs, gradually, until a reluctant dropping consistency is achieved.
Place into a piping bag and pipe small circles, well spaced apart, on a lightly oiled baking tray. Bake at 200 C for 12 minutes then remove and make a hole with a skewer in the flat side. Turn oven down to 180C and leave for a further 5 minutes to dry out the sides of the buns. Leave to cool. And then split the buns in half width-ways.
Whip the cream, mint extract, icing sugar and green food colouring into soft peaks and then carefully fold through the chopped chocolate chips. Spoon into the buns to fill and then pile the buns onto a serving plate.
For the chocolate sauce, place the chocolate and the cream into a heatproof bowl over a pan of barely simmering water. Do not allow the bowl to touch the water. When the chocolate has melted, stir the sauce and pour all over the pile of profiteroles on the dish and serve immediately. If your chocolate sauce is too thick, add boiling water in tsp increments until you have a smooth, pourable sauce. This trick will also work if your sauce has split and become grainy.