Preheat the oven to 400°F (205°C).
Season both sides of the chicken thighs with salt and black pepper. Roast in the oven for 30 minutes or until fully cooked and fat is rendered.
While the chicken is roasting, dice onion, celery, carrots, fennel. Press garlic cloves.
In a large heavy-bottomed pot over medium heat, melt one stick of butter. Add diced vegetables, garlic, and a pinch of salt. Sweat the vegetables for 6-8 minutes, stirring often. I'm using a 6 ¾ qt dutch oven in this recipe.
Stir in the all-purpose flour to create a roux. Cook for 1 minute and deglaze with wine, scraping any fond off the bottom of the pot. Cook for about 30 seconds to cook off the alcohol.
Add in the chicken broth, heavy cream, thyme, bay leaves, and poultry seasoning. Stir well.
Chop the roasted chicken thighs into small bite sized pieces and add to the pot over medium heat along with frozen peas. Stir and simmer on low for 5 minutes to reheat chicken and peas, scraping the bottom of the pot as you go.
In a separate bowl, mix the dry dumpling ingredients: all-purpose flour, salt, baking powder, black pepper. While mixing, stream in the melted (but not hot) butter, and milk and continue stirring until just barely combined.
Taste the chicken gravy mixture for seasoning and adjust with additional salt if needed.
Back to the dumpling dough, using two teaspoons, quenelle the dumpling dough and drop 12-16 dumplings into the pot.
Lower the heat to low, cover with a lid, and cook for 15 minutes or until the dumplings have expanded and cooked through.
Test a dumpling for doneness by cutting into it; it should be fluffy and cooked through, not gluey.
Once the dumplings are cooked, the chicken and dumplings are ready to be enjoyed.