Combine the milk, water and yeast in a jug. Stand for 15 minutes until frothy bubbles appear.
Combine the flour, Natvia and salt in a large mixing bowl making a well in the centre. Pour in the liquid and mix with a knife. Cover with plastic wrap and stand in a warm place for 1 hour until the batter has doubles in size.
Combine the bicarb and warm water and stir through the batter with the parmesan and oregano until smooth. Stand for 15-30 minutes.
Butter the rings well, grease a frying pan and heat to medium-low. Place the greased rings on the frying pan. Half fill the rings and cook until the top dries and is covered in holes, which should take about 10-15 minutes.
Flip over an cook lightly brown the bubbled side if eating straight away, or place on a wire rack to cool. Toast in the microwave to heat later and cover in butter