Use a slow cooker liner or spray with cooking spray. Place the roast in the slow cooker.
In a small bowl, whisk together the Parmesan, honey, soy sauce, basil, garlic, oil, and salt. Pour the sauce over the pork roast. Cover and cook on low for 6-7 hours, or until the internal temperature of the meat reaches 160 degrees.
Remove the roast and cover with foil to keep warm. Skim any fat from the sauce in the slow cooker, then pour the sauce into a medium saucepan. Bring to a boil.
Combine cornstarch and water until smooth. Gradually stir the cornstarch mixture into the pan with the sauce. Bring to a boil and cook, stirring constantly, for about 2 minutes or until thickened. Slice roast and serve with the gravy sauce.
Instant Pot Instructions:
Use saute setting and a bit of oil or butter in the pot to sear roast on each side. Then add additional 1/2 cup water to the sauce ingredients. Add sauce mixture to the pot with the roast and cook on High Pressure for 35 minutes, or until done (about 140-145 degrees F internal temperature). Let pressure natural release, for 10-15 minutes. Remove roast and use saute setting to thicken the sauce with the cornstarch and water, if needed.