Preheat oven to 325 degrees F.

In a bowl, mix sage, salt, pepper, and garlic, thoroughly and then rub all over the pork loin or roast and let rest for 30 minutes. Bring your pork to about room temperature before baking.

Cook in an uncovered roasting pan on the middle oven rack for approximately 3 hours or until a meat thermometer reads at least 150 degrees F.

For the sauce, combine sugar, cornstarch, vinegar, water, and soy sauce in a small saucepan and place on low heat. Stir occasionally until the sauce begins to bubble and slightly thicken.

Then remove from heat and brush the roast with glaze 3 or 4 times during the last 1/2 hour of cooking. Pour remaining sauce over the roast and serve.