Ingredients

  • ⅔ cup onion, very thinly sliced
  • 3 tablespoons extra-virgin olive oil
  • ½ teaspoon finely chopped garlic
  • 1 cup canned Italian plum tomatoes, cut up, with juice
  • Salt to taste
  • 2 tablespoons salt-packed capers, soaked and rinsed, or vinegar-packed capers, drained
  • 2 teaspoons fresh oregano, or 1 teaspoon dried
  • Fresh black pepper or chopped hot red chilies, to taste
  • 2 pounds gray sole fillet