Preheat oven to 400 degrees. While oven heat, begin to prepare rice as directed on package (1/2 cup raw) . Also, take out corn so it may have time to thaw.
Line baking dish with foil; add fish. Season fish with salt and pepper. Bake for 10 minutes, until fish flakes.
Assemble salad by slicing tomatoes into quarters, chopping avocado. Then toss corn, tomatoes, avocado and cilantro into a mixing bowl. Drizzle in olive oil, vinegar; season with salt and pepper; toss together to thoroughly coat vegetables.
Serve fish on a bed of rice with vegetable salad and pineapple on the side.