Shrimp Balls with Water Chestnuts and Spicy Soy Dipping Sauce

4 cloves garlic , smashed and finely chopped

1 (2-inch) piece ginger , grated

6 scallion s, white and green parts, thinly sliced

3 tablespoons fish sauce

2 tablespoons cornstarch

2 egg whites

3 tablespoons soy sauce

2 tablespoons Asian chile paste (sambaal oeleck)

3 tablespoons sesame oil

2 (12-ounce) cans sliced water chestnuts, drained and coarsely chopped

1 cup panko breadcrumbs