Ingredients

2 tablespoons olive oil

1 shell steak, 6 to 8 ounces

Coarse salt and ground pepper

1/2 small onion, thinly sliced

1 yellow bell pepper, quartered lengthwise and thinly sliced crosswise (ribs and seeds removed)

2 garlic cloves, thinly sliced

1/4 teaspoon dried oregano

3 tablespoons red-wine vinegar

2 tablespoons tomato paste

1/3 cup water

Preparation

In a small skillet, heat olive oil over medium heat. Trim and season steak with coarse salt and ground pepper; cook until desired doneness, about 2 minutes per side for medium-rare. Transfer steak to a plate; cover with foil to keep warm.

Make sauce: Add onion to pan; cook, stirring often, until starting to soften, about 3 minutes.

Add bell pepper, garlic, and dried oregano; season with salt and pepper. Cook until bell pepper is crisp-tender, about 5 minutes.

Add red-wine vinegar, and bring to a boil; continue boiling until almost evaporated, about 1 minute. Add tomato paste and 1/3 cup water; cook 1 minute more. Spoon pepper sauce over steak.