Sieve the flour and salt, and add the eggs and milk. Whisk until there are no lumps in the mixture.
In a 18cm (7 in) pan, heat the oil on a high temperature, then turn down slightly. Spoon a small ladle of mixture into the pan and tip the pan so the mixture spreads evenly over the base
Cook on a medium heat for about a minute - until the pancake is starting to brown underneath (you can check this with a palette knife). Flip the pancake in the pan and continue to cook until it is golden brown.
Make all of the pancakes and stack. You can put them in the oven on a very low heat to keep them warm.
Filling:
Melt butter in a large frying pan. Gradually add the sugar and stir over a low heat until melted.
Add the bananas and fry gently until golden and syrupy. Stir in the lemon juice.
Fold the pancakes into four, and cover with the mixture. Serve hot with whipped cream if desired.