Liberally salt and pepper the turkey breast. Heat oil in the pressure cooker using the BROWN setting. Insert the turkey breast and brown on all sides. Remove and set aside. Add onion, garlic, carrots, and celery. Brown until the onion is soft. Add broth, wine, thyme, and bay leaf, cooking for 2 minutes. Place the turkey breast back in the pressure cooker. Cover and set to high pressure. Cook for 40 minutes.
Release the pressure using the quick-release method. Unlock and remove lid. Carefully remove turkey and place on large plate. Cover with foil.
Strain the cooking liquid. Pour it back into the pressure cooker with the cornstarch and water, bring to simmer. Whisk to mix. Season to taste with salt and pepper.
Slice the turkey. Serve with gravy.
Recipe courtesy of Deni, Reprinted with permission.