Cook pasta in salted water until tender but still firm. Meanwhile, whisk oil, cheese, lemon juice and lemon zest to blend. Drain pasta, reserving 1 cup of cooking liquid. Toss pasta with lemon sauce. If needed, add some of the reserved liquid. Season with salt and pepper.
Season fish with salt and red pepper flakes. Heat 3 tablespoons oil in a heavy skillet over medium-high heat. Add fish, and sauté rounded side down for 3 minutes; turn, and sauté 3 minutes or until cooked. Transfer fish to a plate, and set aside.
Add onion to same skillet, and add 1 to 2 tablespoons olive oil. Sauté until translucent.
Add tomatoes with their juices, wine (or chicken broth), garlic, parsley, basil and oregano. Simmer until sauce is reduced slightly or about 10 minutes.
Gently return fish and any juice to tomato mixture to absorb spices.
Serve over Lemon Pasta.
Serves 4