In blender, purée olive oil, garlic, shallot, sage, salt, and pepper until blended. Rub mixture over roast, concentrating on areas between chops.
Transfer roast to roasting pan. Cover with foil and refrigerate overnight or up to 48 hours.
Let sit at room temperature 1 hour before roasting.
Preheat oven to 450°F. Turn roast upside down (rib bones down) in roasting pan. Roast 15 minutes, then reduce heat to 350°F and roast until instant-read thermometer registers 155°F when inserted 2 inches into center of meat (do not touch bones), about 1 1/2 hours more.
In large skillet over moderately high heat, melt butter.
Add poblanos, onion, celery, and garlic, and sauté, stirring, until softened, 7 to 10 minutes.
In large bowl, combine corn bread and sautéed vegetables.
Add eggs, 1/4 cup chicken stock, cilantro, hot sauce, salt, and pepper. If mixture seems dry, mix in additional stock, slowly, until stuffing is lightly moistened. Press into 2-quart casserole dish. Thirty minutes before removing roast, transfer stuffing to oven.
Bake until golden, about 45 minutes.
When roast is done, remove from oven, tent with foil, and let stand at least 15 minutes (it will stay warm 1 hour). When stuffing is done, mound 1/2 on platter. Flip roast upright on top of stuffing. Fill center of roast with remaining stuffing. Slice at table.
