Roast the sesame seeds in a dry pan over medium heat, stirring constantly, for 2-3 minutes until golden yellow. Remove from pan and set aside.
Peel the bananas. Cut each banana in half lengthwise, then cut each half in half crosswise to create 4 pieces per banana.
In a high-walled pan, heat 3/4 of the coconut milk over medium heat. Add the brown sugar and salt, stirring constantly until completely dissolved. Add the banana pieces and cook for 2-3 minutes.
Add the remaining coconut milk to the pan and heat through over medium heat without allowing it to boil.
Divide the banana and coconut milk mixture among 4 plates. Sprinkle the roasted sesame seeds over each serving.