Serve this flavorful Instant Pot pork dish over polenta.
Sprinkle pork with 1/2 teaspoon of the salt and 1/4 teaspoon of the pepper. Remove lid from a 6-quart Instant Pot®. Press [Sauté]; use [Adjust] to select "More" mode. When the word "Hot" appears, swirl in oil. Add pork to inner pot; cook 10 minutes, browning on all sides. Remove pork from cooker.
Add fennel and onion to drippings in pot; cook, stirring constantly, 6 minutes or until lightly browned. Add ginger and garlic; cook, stirring constantly, 1 minute. Stir in apple. Add mustard, next 4 ingredients (through ginger beer), remaining 1/2 teaspoon salt, and remaining 1/4 teaspoon pepper, stirring gently. Nestle pork in center of vegetable mixture. Turn cooker off.
Close and lock the lid of the Instant Pot®. Turn the steam release handle to "Venting" position. Press [Slow Cook], and use [Adjust] to select "Less" mode. Press [-] or [+] to choose 2 hours 30 minutes cook time. When time is up, an instant- read thermometer inserted in center of pork should register 145°F. (Cook additional time, if necessary.) Remove lid, leaving cooker in automatic warming mode. Remove pork from cooker; place on a cutting board or work surface, and let stand 15 minutes.
While pork stands, strain vegetable mixture through a sieve into a medium saucepan. Return vegetables to inner pot. Combine cornstarch and 2 tablespoons water in a small bowl; add cornstarch mixture to cooking liquid in saucepan. Bring to a boil over medium-high heat, stirring constantly; cook, stirring constantly, 1 minute or until thickened. Cut pork into thin slices; serve pork with vegetable mixture and sauce. Garnish with thyme leaves, if desired.