Heat oven to 325 degrees.
In a large, oven proof pot, heat olive oil. Season roast with salt and pepper then sear until brown on each side. Remove beef from pot and set aside.
Add onions to skillet and cook until slightly golden. Add garlic and tomato paste. Stir to incorporate, scraping browned bits from bottom of pot. Cook for 3 minutes.
Add roast back to pot. Pour all contents of jar including pepper and juice over the roast. Cover and place in oven for 2 and 1/2 hours.
Remove roast from oven. Let rest for 15 minutes then slice and serve with drippings.