Sauté Mirepoix Aromatics: In a large 6-quart enameled Dutch oven or heavy soup pot, melt butter with olive oil over medium heat. Add diced onions, sliced carrots, and celery. Season with 1 teaspoon salt and 0.5 teaspoon pepper. Sauté for 6 to 8 minutes until vegetables soften and onions turn translucent. Stir in minced garlic, fresh thyme, and poultry seasoning; cook for 60 seconds until fragrant.

Create the Velvety Gravy Base: Sprinkle 1/3 cup all-purpose flour over the sautéed vegetables. Stir continuously for 2 minutes to cook out raw flour flavor. Slowly pour in chicken bone broth while stirring constantly to dissolve any browned bits from the pot bottom. Pour in the heavy cream. Bring the mixture to a lively simmer over medium-high heat, then reduce to medium-low; simmer gently for 8 to 10 minutes until the gravy thickens into a glossy, velvety consistency.

Whisk the Dumpling Dough: While the broth simmers, prepare the dumpling dough. In a medium mixing bowl, whisk together flour, baking powder, baking soda, salt, and chopped parsley. Cut in the cold cubed butter using a pastry blender, two knives, or your fingertips until the mixture resembles coarse meal with pea-sized butter bits. Pour in cold buttermilk and stir gently with a fork just until a soft, sticky dough forms. Do not overmix, or dumplings will be dense!

Fold in Chicken & Drop Dumplings: Stir the shredded cooked chicken and sweet frozen peas into the simmering stew. Taste and adjust salt and pepper if needed. Using a standard tablespoon or 2-tablespoon cookie scoop, drop rounded balls of dough directly onto the gently bubbling surface of the stew, spacing them evenly (about 12 to 14 dumplings total).

Steam Cover-Tight (The Golden Rule): Immediately cover the pot with a heavy, tight-fitting lid. Reduce heat to LOW so the stew maintains a gentle simmer. Cook covered for strictly 15 minutes WITHOUT lifting the lid! (Lifting the lid allows trapped steam to escape, which causes dumplings to collapse).

Check Doneness & Serve Warm: After 15 minutes, remove the lid. The dumplings should be doubled in size, puffed, and dry on top. Insert a toothpick into the center of a dumpling—it should come out clean without wet dough. Ladle generous portions into wide bowls, spooning rich chicken gravy and tender vegetables over and around the cloud-soft dumplings. Garnish with freshly cracked pepper and chopped parsley!