Season the chicken with 1 teaspoon each salt and pepper. Add the olive oil to a 6- or 8-quart Instant Pot and set to sauté. Working in batches, add the chicken to the pot and cook until browned, 21⁄2 to 3 minutes per side. Remove the chicken to a plate. Add the celery, carrots, garlic, onion, rosemary, sage and thyme to the pot and cook, stirring, for 1 minute. Add the wine and stir, scraping up the bottom of the pot. Cook until the wine is reduced by at least half, about 2 minutes. Add the broth, rice and 1⁄2 cup water and stir. Add the chicken and any juices from the plate; add the bay leaf. Put on and lock the lid, making sure the steam valve is in the sealing position. Set to pressure-cook on high for 25 minutes. After the time is up, carefully turn the valve to the venting position and let the steam release. Unlock and remove the lid, being careful of any remaining steam. Remove the chicken from the pot and shred with two forks in a bowl. Meanwhile, in a small bowl, mash together the butter and flour with a fork to make a paste. Return the chicken to the pot. Add the butter mixture, stirring to thicken. Set the Instant Pot to sauté. Add the kale and cook 2 minutes. Stir in the half-and-half and bring to a simmer, then press cancel. Just before serving, remove the bay leaf, add the lemon juice and stir. Season with salt and pepper.