Heat a dutch oven over medium high heat. Season the chicken thighs with the cajun seasoning.
Once the dutch oven is hot, add in the olive oil. Sear the chicken on both sides for about 3 minutes per side, we are just getting some color on it, it will finish cooking later. Remove and set aside.
Reduce the heat to medium and melt the butter. Once the butter is melted add in the onions, carrots and celery. Stir altogether and let cook for a few minutes until the onions are translucent & everything is softer. Season with the pepper and poultry seasoning, give this a stir.
Start gradually whisking in the flour until it is completely dissolved and cooked a bit for about 3 minutes. Gradually pour in the chicken broth and start whisking to combine, there should be no lumps from the flour. Add in the fresh thyme and bay leaf. Turn the heat to medium high and let this come to a boil.
While the liquid is beginning to boil, cut the chicken thighs into bite size pieces. Add the chicken thighs into the pot. Stir to combine. Reduce the heat to low.
In the meantime make the dumplings. To a mixing bowl add the flour, baking powder and salt, whisk this together. Gradually add in the buttermilk and melted butter. If the dough seems dry, add in a tablespoon of buttermilk. Gently stir to combine everything, you don’t want to overmix the dough, this will result in dense dumplings.
Separate the dough into small pieces using a cookie scoop or spoon and drop them into the pot but all over, not in the same area.
Cover the pot and put the heat to medium low and let this simmer for 15 minutes. After the 15 minutes is up, remove the lid and stir in the heavy cream if using. Gently push the dumplings into the soup and let simmer for about 5 minutes.
Remove from the heat and serve. Eat and enjoy!