For the dumplings: Whisk the flour, parsley, cornmeal, chives, baking powder and salt in a medium bowl. Stir in the milk and melted butter until the batter just comes together; set aside. For the chicken: Set a 6-quart Instant Pot to sauté on high. Add the olive oil and butter and let the butter melt, stirring constantly so it doesn’t burn. Add the carrots, celery, onion, 1 teaspoon salt and ¼ teaspoon pepper and cook, stirring, until softened, 3 to 4 minutes. Stir in the flour, thyme and turmeric until the vegetables are well coated. Add the chicken, the remaining ½ teaspoon salt and a few grinds of pepper and stir until coated. Stir the chicken broth into the Instant Pot. Press cancel to turn off the pot. Carefully scoop about 12 mounds of dumpling batter (2 tablespoons each) into the pot, spacing them evenly. Lock the lid, making sure the steam valve is in the sealing position. Set to pressure-cook on high for 3 minutes. When the time is up, carefully turn the steam valve to the venting position and let the steam release. Unlock and remove the lid, being careful of any remaining steam. Ladle the chicken and dumplings into bowls.