In a bowl or jug, whisk together the flour, milk and egg until you have a smooth batter. Let stand for 20 minutes. Line a dinner plate with baking parchment.
Put a 20cm non-stick frying pan over a medium heat, add a little of the oil and swirl around the pan. Pour a ladleful of batter into the pan, swirling so the batter covers the base in a thin layer. Cook the pancake for 30 seconds to 1 minute, then flip it over and cook the other side. Remove from the pan onto the prepared plate.
Repeat with the remaining mixture until you have 8 pancakes, layering with a sheet of baking parchment between each one to prevent sticking.
Slice the bananas, put in a frying pan with a knob of butter and fry for a few minutes. Add the sesame seeds, stirring, until toasted. Spoon on top of the pancakes, add a squeeze of toffee sauce and serve with the ice cream.