Sprinkle 3 pounds chicken wings with salt and pepper to taste, then place the wings in the bottom of your slow cooker in a single layer if possible.
In a small mixing bowl, whisk together 1 cup honey, 1/2 cup soy sauce, 2 teaspoons minced garlic, 1 teaspoon ground ginger, and 2 tablespoons vegetable oil until smooth. Pour the sauce evenly over the wings and turn the wings once to coat.
Cover and cook on LOW for 6–8 hours or on HIGH for 4–5 hours.
When the wings are done, use tongs or a slotted spoon to transfer the wings to a plate and leave the sauce in the slow cooker.
Pour the sauce from the slow cooker into a saucepan and bring it to a boil over medium-high heat. Reserve a small amount of the hot sauce in a bowl, whisk the 1 tablespoon cornstarch into the reserved sauce until smooth, then return the cornstarch slurry to the saucepan. Continue boiling and stirring until the sauce thickens, about 1–2 minutes.
Return the wings to the slow cooker (or place the wings in a large bowl), pour the thickened sauce over them, and toss gently to coat evenly. Serve.