2 tablespoons olive oil
1 1/2 pounds boneless, skinless chicken thighs, cut into 2-inch chunks
Coarse salt and ground pepper
4 cloves garlic, minced
1 tablespoon chopped fresh oregano (or 1 teaspoon dried)
1/4 teaspoon crushed red pepper
1/4 cup red-wine vinegar
1 red bell pepper, ribs and seeds removed, cut into 1/2-inch strips
1 package (10 ounces) frozen artichoke hearts, thawed and halved
4 ounces feta cheese, crumbled
Heat oil in a large skillet over high heat. Season chicken with salt and pepper; add to skillet, and brown on all sides, about 10 minutes.
Reduce heat to medium; add garlic, oregano, and crushed red pepper to skillet. Cook, stirring constantly, until fragrant, 1 to 2 minutes. Add vinegar; cook, scraping up browned bits from bottom of skillet with a wooden spoon, until liquid has evaporated, 1 to 2 minutes.
Add 2 cups water to skillet, and simmer over medium heat 10 minutes. Add bell pepper and artichoke hearts; simmer until chicken is tender and liquid has thickened, 5 to 10 minutes. Remove from heat. Stir in feta cheese, season with salt and pepper as desired, and serve.