Preheat the oven to 200C/180C Fan/Gas 6. Line a 6 hole muffin tin.
In a large bowl, combine the flour, sugar and baking powder. Make a well, and pour in the liquid ingredients (milk, butter, oil, vanilla and egg). Stir gently with a wooden spoon until just combined.
Add the strawberries and chocolate and mix again. Scoop into the lined muffin tin - filling to just over 2/3rds full.
Bake 15 minutes, until golden brown and a skewer inserted comes out clean. Let cool on a wire rack before serving (and wonderful eaten warm).