Preheat the oven to 400˚F (200˚C).
Grease a 6-cup muffin tin with nonstick spray.
In a bowl, combine rice, onion, scallions, garlic, salt, soy sauce, and egg.
Mix well.
Divide into muffin cups and with a spoon press the sides against the cups and bottom down to make an indent in the centers.
Bake 35 minutes and remove from tins.
Fill with sliced chicken and sauce.