How to Make It
Stir together grits, flour, onion, and baking powder in a heat-resistant bowl until combined. Place milk, butter, and salt in a small saucepan; bring to a boil over high, stirring occasionally. Pour over grits mixture, stirring to combine. Let stand 5 minutes.
Fill a large pot with water to ½-inch depth; bring to a boil over medium-high. Coat a steamer basket with cooking spray.
Shape grits mixture into 9 balls (about 2 tablespoons each). Place in prepared steamer basket. Place basket in pot of boiling water, making sure water does not touch bottom of the basket. Cover and cook until dumplings are puffy and slightly firm to the touch, about 15 minutes.
Transfer dumplings to serving bowls. If dumplings stick together, gently pull or cut them apart. Pour warm broth or soup over dumplings in bowls, and serve. (Dumplings will expand in broth.)