Make the dough: In a large bowl, mix flour, salt, sugar, condensed milk, egg, and water. Knead until soft and smooth (8–10 minutes). Brush with oil, cover, and rest for 30 minutes.
Slice the bananas: Cut bananas into thin slices. Beat one egg in a small bowl.
Stretch the dough: Take one dough ball (about golf ball size). Flatten and gently stretch it until thin and almost see-through.
Cook the roti: Heat a non-stick pan with oil. Place the stretched dough in the pan. Add banana slices and pour the beaten egg on top.
Fold the roti: Fold the edges over to enclose the filling in a square shape.
Fry until golden: Cook 2–3 minutes per side until crispy and golden brown.
Top and serve: Remove from the pan, cut into squares, and drizzle generously with condensed milk. Serve hot.
