Pound the beef round steak with a meat mallet until it is approximately 1/2 inch thick to tenderize.
Season both sides of the beef with the sea salt and black pepper.
Heat the avocado oil in a large heavy skillet over medium-high heat.
Sear the beef for 2-3 minutes per side until a golden-brown crust forms, then remove from the pan and set aside.
In the same skillet, add the diced onion, green bell pepper, and celery, sautéing for 5 minutes until the vegetables soften.
Stir in the minced garlic and cook for 1 minute until fragrant.
Pour in the crushed tomatoes, beef bone broth, Worcestershire sauce, and dried oregano, stirring to scrape up any browned bits from the bottom of the pan.
Return the steak to the skillet, spooning the tomato mixture over the top to coat.
Reduce the heat to low, cover the pan tightly, and simmer for 45 to 60 minutes until the beef is fork-tender and the sauce has thickened.