Here's a delicious recipe my family loves. Works well with any mild fish--I use cod, scrod, tilapia or haddock. Don't be afraid of the anchovy, but you can leave it out of you wish.
Squeeze the juice from half a lemon over one pound fish fillets that have been cut into serving portions. Sprinkle with a bit of salt and pepper. Arrange in a baking dish.
In a large skillet, on medium heat, warm 1 Tbs. olive oil. Add a teaspoon anchovy paste or a good chopped anchovy or two( you can leave it out, but this tiny bit really adds a complex flavor, not "fishy") two sliced small onions (or 1 large), 1 sliced sweet red pepper, and one stalk chopped celery. Let the vegetables soften. Add 3 cloves chopped garlic, 6 sliced black olives and 3 sliced large garden tomatoes. Cook for 5-10 minutes. Add salt and pepper to taste and a handful of a mixture of chopped fresh parsley, basil, thyme. Let cool, then spoon the mixture over the fish. Bake in a preheated 400 oven 15-20 minutes, or until fish flakes.