Preheat oven to 300°.
Heat olive oil in a large Dutch oven over medium-high heat. Sprinkle roast with salt and pepper. Add roast to pan, browning on all sides (about 8 minutes). Remove from pan. Add onion to pan; sauté 8 minutes or until browned. Return roast to pan. Combine broth, ketchup, and Worcestershire; pour over roast. Add tomato; bring to a simmer.
Cover and bake at 300° for 2 1/2 hours or until tender. Add potatoes and carrots; cover and bake an additional 30 minutes or until vegetables are tender. Stir in lemon juice. Garnish with parsley, if desired.