In a small bowl combine the onions, celery, bell peppers, butter and
seasonings, mix well.
Place roast in a large roasing pan, fat side up. With a large knife
make 6 to 12 deep slits in the meat (to form pockets) down to a depth of
about 1/2 inch from the bottom; do not cut all the way through. Fill the
pockets to their depths with the vegetable mixture, reserving about 1
tablespoon of the vegetables to rub over the top of the roast.
Bake uncovered at 300 degrees F (150 degrees C / gas mark 2) until a
meat thermometer reads about 160 degrees F for medium doneness, about 3
hours. For rarer roast, cook until thermometer reads 140 degrees F.
Serve immediately topped with some of the pan drippings if you like.
To make in a slow cooker: Add 1 cup beef broth to the slow cooker. Cook on LOW for 8 hours.
Recipe credit: Paul Prudhommes Louisiana Kitchen through Big Oven