Blueberries freeze well so keep a bag in the freezer for when they are out of season
Heat the oven to 200C/fan 180C/gas 6 and line a 6-hole muffin tin
with paper cases. Mix the egg, melted butter and milk quickly into
the dry ingredients with the blueberries and chocolate (don’t overmix,
it should be a bit lumpy). Divide between the cases and bake
for 25 minutes until risen and golden and cooked through.