Sift the dry ingredients into a large bowl and mix well. Season with salt and pepper - but be careful not to over salt as the stock powder will contain salt.
Stir in the ham and cheese, and chives if using, mix again.
Add the egg, milk and olive oil - mix well - but do NOT over mix - just enough to combine the ingredients together. Adjust the consistency if too dry by adding a little more milk - the mixture should be a soft dropping consistency.
Spoon mixture into the prepared muffin/bun tray/pan and bake in the preheated oven for 20 to 25 minutes, or until the muffins are well risen and golden brown.
Remove from the oven and allow to cool slightly on a wire rack.
Serve whilst warm - delicious if spread with butter or soft cheese!