Place 2 cups long-grain white rice in a fine-mesh strainer and run under cold water, stirring occasionally, until the water runs clear, about 2 minutes. Place the rinsed rice, 1/4 teaspoon salt, and 2 cups water in a 2-quart ovensafe bowl, 6-inch (2-inch deep) round cake pan, or steamer pot or pan that will fit inside your Instant Pot; set aside.
Grate 2 garlic cloves and 1 tablespoon peeled ginger, and place in the Instant Pot or electric pressure cooker. Add 1/2 cup low-sodium soy sauce or tamari, 1/2 cup packed light brown sugar, and 1/4 cup rice vinegar, and whisk to combine. Add 2 pounds chicken thighs and spoon a bit of sauce over each thigh to coat.
Set a trivet over the chicken. Place the pan of rice, which will cook uncovered, onto the trivet. Lock the lid in place and make sure the pressure valve is set to seal. Set to cook on HIGH pressure for 6 minutes. Meanwhile, remove any tough strings from 8 ounces sugar snap peas and peel and thinly slice 2 large carrots into rounds.
After the cook time is up, let the pressure naturally release for 10 minutes. Quick release any remaining pressure. Open the pressure cooker and carefully remove the pan of rice. Using tongs, transfer the chicken to a clean cutting board.
Stir the snap peas and carrots into the sauce in the Instant Pot, turn it onto the Sauté function, and cook for 5 minutes. Meanwhile, whisk 2 tablespoons cornstarch and 2 tablespoons water together in a small bowl.
Add the cornstarch slurry to the sauce, bring to a simmer, and cook until the sauce is thickened and the vegetables are tender crisp, about 5 minutes. Cut the chicken into bite-sized pieces. Serve over the rice with the vegetables and sauce.
