Heat the olive oil in a large Dutch oven over medium heat. Add the onions and cook for 3-4 minutes or until softened. Add the carrots, celery, and minced garlic and cook, stirring constantly for 1 minute.
Add the chicken broth, dried basil, bouillon granules, sea salt, and freshly cracked pepper, to taste. Cover and cook on medium-low for 45 minutes or until the vegetables are soft.
Combine the flour with basil, garlic powder, salt, and baking powder in a large bowl. Cut in the butter with a pastry cutter or 2 knives until the mixture resembles a coarse meal.
Combine buttermilk and egg, stirring with a whisk. Add buttermilk mixture to flour mixture, stirring until just combined.
Add the chicken to the soup then taste to re-season with sea salt and freshly cracked pepper, if needed; bring to a simmer over medium-high heat.
Combine the cornstarch with the chicken broth and mix thoroughly to make a slurry. Add slurry to the soup, and simmer for 3 minutes.
Drop dumpling dough, 1-2 tsp per dumpling, (I used two spoons to drop them into the soup) into the chicken soup.
Cover and cook for 7 minutes (DO NOT LET THE BROTH BOIL).
Add the chopped parsley to the soup and serve. Enjoy.