Preheat oven to 325°. If starting with round steak instead of cubed steak, pound it thoroughly with a meat mallet. Cut the steaks into serving-sized pieces.
Combine the flour, salt, and pepper. Dredge each piece of beef. Heat the oil over medium heat in a Dutch oven or oven proof skillet with a lid. Working in batches, brown the steaks until well colored on both sides.
When all steaks are browned, return to the pot. Add the onion, canned tomatoes, and Worcestershire sauce. Cover and put the pot in the oven. Cook for 2 hours or until fork-tender.
If you'd like more gravy or a thinner gravy, remove the steaks to a serving plate while the pot is still hot. Whisk in the optional broth a quarter cup at a time until you reach the consistency you want.
