In a medium saucepan, cover the bean with water and cook them on medium heat until tender, about 30-40 minutes. Add a few pinches of salt, transfer the beans to a bowl and set aside when done.
Using the same pan, combine white rice and glutinous rice and simmer on medium heat with 3 ½ cups of water. Once the rice softens, add in the beans and gently mix until combined.
In a small saucepan, cook the coconut milk with water on medium heat. Do not let it boil vigorously.
Add salt and sugar. Make a slurry with the cornstarch and add it to the coconut milk. Continue to stir until the mixture thickens and remove it from the heat.
Combine the sesame seeds and salt.
Serve hot with the coconut sauce and sesame salt on the side.