Put the flour and bicarbonate of soda into a large mixing bowl then add the eggs and yogurt. Slowly whisk in the milk little by little, whisking all the time until the mixture is smooth and frothy. Stir in the orange rind.
Pour a little oil into a large nonstick frying pan, then wipe around the pan with a folded piece of kitchen towel. Heat up the pan then carefully drop large spoonfuls of the mixture into the pan, dot with Chilean blueberries and cook until tiny bubbles begin to show on the top and the undersides are golden around the edges.
Turn the pancakes over with a nonstick egg slice or palette knife and cook the second side until golden. Take these hot cakes out of the pan and keep hot in a folded teacloth while you cook the rest of the mixture in the same way, greasing the pan with the kitchen towel between batches.
Serve 3 or 4 per portion, stacked up on plates topped with a knob of butter, a drizzle of maple syrup and some extra Chilean blueberries.