IN A BLENDER; Place the ingredients (except baking soda) in the blender and blend until you have a smooth batter. Pour the batter into a bowl.
ONE-BOWL METHOD; Whisk together semolina, plain flour, sugar, salt, and instant yeast until well combined. Make a well in the center, add the egg and then whisk slightly. Gradually, stir in milk and water, and then whisk until you have a smooth and thin batter without lumps.
TWO-BOWL METHOD; Whisk together dry ingredients (semolina, plain flour, salt, sugar, and instant yeast) in a large bowl. Whisk together wet ingredients (egg, milk, and water) in a separate bowl. Add the egg mixture to the flour mixture and whisk until you have a smooth batter without lumps.
Cover and let the batter rest for about 30 minutes in a warm place until it is foamy. Don’t rest your batter too long and don’t let it bubble too much, otherwise, you will not get a lot of bubbles on the surface of your pancakes.
Just before you cook the batter, stir in baking soda after dissolving it in some water. Rest the batter for about 5 minutes.
If your batter is thick after resting time (semolina tends to absorb a lot of liquid), add water a little at a time as needed to thin it. And let the batter rest again for about 10 minutes.