In a large bowl, combine the beef with olive oil, minced garlic, oregano, red wine vinegar, salt, and pepper. Mix thoroughly and cover to marinate in the refrigerator for at least 15 minutes.

Heat 2 tablespoons of olive oil in a large skillet over medium heat. Add chopped onion and diced bell pepper, cooking until the onion is translucent, about 5-7 minutes.

Increase to medium-high heat and add the marinated beef, searing for about 5-8 minutes until nicely browned on all sides.

Deglaze the pan with 1 cup of beef broth, scraping up browned bits. Bring to a boil for 1-2 minutes.

Reduce heat to low and cover. Let simmer for 30 minutes, stirring occasionally.

Taste and adjust seasoning with extra salt, pepper, or lemon juice as desired.

Garnish with parsley and serve hot with rice, bread, or salad.