Combine self raising flour, Edgell Corn Kernels, Edgell Capsicum, and spring onions in a large bowl.
Combine buttermilk, oil, eggs and seeded mustard in a small bowl then stir into the dry ingredients until just combined. Spoon the mixture into 12 greased 1/3 cup capacity muffin pans and sprinkle with grated cheese.
Bake in a preheated oven at 200°C for approximately 15 minutes or until cooked. Serve warm or cold.