Season the chicken. Set an electric pressure cooker to Browning or place a stovetop pressure cooker over high heat. Heat the oil in the pressure cooker. Add the chicken and cook, turning, for 10 minutes or until browned. Transfer the chicken to a plate.
Change the electric pressure cooker setting to Sauté or reduce heat to medium-high. Add leek, speck, shallots and mushrooms. Cook, stirring often, for 10 minutes or until lightly caramelised. Place chicken in the pressure cooker, nestled among the speck mixture. Add the stock, wine, garlic and tarragon to the pressure cooker. Seal the pressure cooker. Cook on Low pressure for 30 minutes. Turn off heat and immediately release the pressure according to the manufacturer’s instructions. Transfer the chicken to a serving platter and cover to keep warm.
Add the fennel and carrots to mixture in the pressure cooker. Seal the pressure cooker and cook on Low pressure for 5 minutes. Turn off the heat and immediately release the pressure according to the manufacturer’s instructions.
Transfer the vegetables to the serving platter with the chicken and season. Spoon the sauce over the vegetables.
