Steam or boil the sweet potatoes until soft, about 15-20 minutes. Drain and mash until smooth.
In a mixing bowl, combine the mashed sweet potatoes with glutinous rice flour, sugar, and milk. Knead until a smooth, slightly sticky dough forms.
Divide the dough into small portions and shape them into round discs or balls.
Heat a non-stick pan over medium heat and lightly grease it with oil. Place the mochi bites in the pan and cook for 3-4 minutes on each side until golden brown.
Remove from heat and sprinkle with toasted sesame seeds. Serve warm and enjoy!