Dry the steaks with paper towels, then sprinkle 1 teaspoon of the salt and all the black pepper over both sides.

Heat 1 tablespoon of the olive oil in a large skillet over medium-high heat, tilting the pan to coat the bottom.

When the oil starts to shimmer, lay in the steaks and sear them until a golden-brown crust forms, about 2 minutes on the first side and 1 minute on the second. Move the steaks to a plate and lower the heat to medium.

Pour the remaining 1 tablespoon olive oil into the skillet and swirl it around. Add the onion and crushed red pepper flakes. Cook, stirring now and then, until the onion softens, about 3 minutes.

Stir in the garlic and cook for 1 minute. Pour in the broth and vinegar mixture, scraping up any browned bits from the skillet bottom. Add the diced tomatoes, the remaining 1/2 teaspoon salt, and the oregano. Stir everything together.

Let the sauce come to a gentle simmer and cook for 10 minutes. Return the steaks and any juices on the plate to the skillet. Cook just until the steaks are heated through, about 3 minutes more.

Divide the steaks and sauce evenly among plates. Scatter the parsley over the top and serve with toasted crusty baguette or focaccia for dipping.