Add roast beef and broth to the slow cooker. And layer the sliced onions, bell peppers, and garlic around the roast.
Add the salt, Italian seasonings, and tomato paste to the crock pot. Drizzle the roast and vegetables with the extra virgin olive oil.
Place lid on slow cooker and set to high for about 4-5 hours (or low for 6-8 hours) until roast is fork tender.
Remove meat and place on a serving platter. Arrange the onion, green bell peppers, and garlic to the top. Drizzle a little of the tomato juices over the top of the meat.
If the tomato paste has not completely mixed in, give it a gentle stir with the other juices until blended.