Preheat your oven to 200°C. Pop your sausages in for 25 minutes, or until nicely coloured and cooked through.
Meanwhile, make your batter. Pop the flour, baking powder, salt, mustard, beer and cayenne in a bowl and whisk until smooth.
Chop your sausages in half and skewer each with a cocktail stick. Heat your oil to 190°C. Dip each piece of sausage in the batter then chuck into the oil. Fry until nicely golden, about 2-3 minutes. Drain on kitchen towel.
