Add wheat flour, baking powder, baking soda, sugar, salt and lemon juice to a large bowl. Mix well.
Gradually add milk and bring the mixture together into a very soft dough.
If the dough feels sticky, add 1 teaspoon oil and knead again.
Knead the dough well for 5–10 minutes until smooth, soft and stretchy.
Divide the dough into approximately 12 small portions and shape each into a smooth ball.
Cover the dough balls with a clean cloth.
Dust the work surface lightly with dry flour and roll each ball into a thick roti.
Heat a tawa and cook the naan over low heat, flipping once the first side is cooked.
Continue cooking until the naan puffs and develops light cooked spots.
Mix butter with chopped coriander and chilli flakes and brush it over the hot naan.
Repeat with the remaining dough and serve warm with chutney or sauce.