In a medium bowl, stir together the flour, baking powder, sugar and salt.
Cut in the butter.
Add the milk and mix just until combined. Set aside.
Make the soup:
In a medium saucepan, combine the broth, frozen vegetables, onions, water, basil, oregano, dill, salt, garlic powder and pepper. *If you are using fresh herbs, add them in after the milk mixture.**
Bring to a boil.
In a small bowl, whisk together the flour and milk until smooth.
Drizzle into the boiling mixture. Cook and stir over medium low heat until the mixture has thickened a bit.
Drop the dumpling dough by tablespoons into the boiling stew. (We make about 15 dumplings.)
Simmer over low heat (so the milk does not burn), covered, for 15 minutes. Do NOT open the lid.
A toothpick inserted into the dumpling should come out clean with no doughiness.
Stir in the cooked chicken.
Serve immediately. Makes about 6 cups of stew (4 servings).