How to Make It
In a large skillet, heat the olive oil. Add the peppers, onion and brown sugar, season with salt and cook over high moderate heat, stirring occasionally, until the vegetables are soft and beginning to caramelize, about 10 minutes. Add the garlic and cook until it is softened, about 3 minutes more. Stir in the oregano and remove from the heat.
Light a grill. Grill the sausages over high heat, turning often, until they are cooked through, about 10 minutes. Transfer the sausage to the hoagie buns and top with the peppers and onions; serve.