For the pork roast: In a blender, puree the oil, garlic, and sage until smooth. Season with salt and pepper. Rub the mixture over the pork roast, making sure to cover the areas between the chops. Transfer the pork to a roasting pan and cover it with foil. Refrigerate it for at least 2 hours and up to 48 hours. Let stand at room temperature for 1 hour before roasting.
Preheat the oven to 450 degrees F.
Turn the roast upside down (rib bones down) in the roasting pan. Roast for 15 minutes, and then reduce the heat to 350 degrees F and roast until an instant-read thermometer reads 155 degrees F when inserted 2 inches into the center of the meat, about 1 1/2 hours more.
For the stuffing: Melt the butter in a large skillet over medium-high heat. Add the green pepper, onion, celery, and garlic and cook until softened, stirring occasionally, for 7 to 10 minutes. In a large bowl, combine the vegetable mixture with the crumbled cornbread. Add the eggs, broth, rosemary, cilantro, hot sauce, salt, and pepper and stir to combine. Slowly stir in more broth, if needed, until the stuffing is moistened. Press the stuffing into a 2-quart casserole.
Thirty minutes before removing the roast, place the stuffing in the oven. Bake until golden, about 45 minutes.
When the roast is done, remove it from the oven, tent with foil, and let stand for at least 15 minutes. When the stuffing is done, mound half of it on a serving platter. Flip the roast upright on top of the stuffing. Fill the center of the roast with the remaining stuffing. Slice at the table.