Red Snapper With Tomato Sauce

3 lbs red snapper salt and pepper 2 onions , peeled and sliced 1 carrot , peeled and diced 2 tablespoons minced parsley 1/4 cup celery , sliced 1 quart water[...]

4 teaspoons extra-virgin olive oil, divided 1/2 teaspoon kosher salt, divided 1/2 teaspoon freshly ground black pepper, divided 2 (6-ounce) snapper fillets 2[...]