Cook the sweetcorn in a saucepan of boiling water for 1 minute. Drain well.
Mix together the flour, cornmeal, baking powder, cheese, chives and a little salt and pepper in a bowl. Stir in the ham and sweetcorn. Beat together the eggs, milk and oil in a jug. Add to the dry ingredients and stir together using a large metal spoon until just combined.
Divide the mixture evenly between paper muffin cases arranged in a 12-hole muffin tray. Bake in a preheated oven, 220°C (425°F), Gas Mark 7, for 20 minutes or until golden and just firm to the touch. Transfer to a wire rack to cool.