Mix milk and lemon juice in a bowl and let this rest at least a couple of minutes.

In a separate bowl put flour, sugar, baking powder, baking soda, and salt.

In the first bowl mix the egg and the butter.

Heat a pan (add cooking spray to make sure the pancake will not stick) at medium heat while mixing the dry ingredients with the wet ones until the batter is smooth.

Start putting some batter on the pan, you will notice it will start to raise a little. Use a spatula to check it is not sticking and to check it's not burning :)

When you can notice several bubbles on the uncooked surface, even if they are staying unburst under the surface (or if the other side is burning [turn down the heat...]), use the spatula to quickly turn the pancake.

this side will take a little less to brown, check it lifting it a little with the spatula.