In a large pot or Dutch oven, heat the olive oil over medium-low heat. Add the onion and celery and saute until the onion is translucent, about 10 minutes.
While the onion and celery saute, make the dumplings by mixing together the flour, salt, pepper and baking powder in a medium bowl. In a liquid measuring cup, whisk together the milk and egg then add that to the dry ingredients with the melted butter. Mix until combined, being careful not to overmix. Set the dumpling batter aside.
Once the onions are translucent, add the garlic and cook for about a minute more until fragrant.
Then add the chicken stock, the thyme and the next 5 ingredients ending with the pepper. stirring constantly, and bring to a simmer over low heat.
In a small bowl, whisk together the flour and water or broth together to create a slurry then whisk that into the chicken broth mixture and bring up to just a boil until it thickens slightly. Then add the shredded chicken, cubed butternut squash and frozen mixed vegetables and return to a boil, then adjust to a simmer.
Using a tablespoon or a small ice cream scoop, drop scoops of the dumpling batter into the boiling liquid. Reduce the heat, if necessary, to a simmer and cook, uncovered, for 10 minutes. Then cover and cook about an additional 10 minutes until the dumplings are cooked and the squash is tender.
Garnish each serving with fresh parsley and enjoy.
*I like to use a cooked rotisserie chicken from the grocery store when I want to make this a super quick dinner.
*If you happen to have leftover evaporated milk or cream, you can use that in place of the half & half.
*Store any leftovers in an airtight container in the refrigerator for up to 4 days. To re-heat, you can add a splash of chicken stock to loosen it up a bit.
*This can be frozen for up to 3 months. Thaw in the refrigerator overnight, then reheat over the stove on low heat adding extra liquid as needed.