While the rice (and maybe vegetable) is cooking, place a sheet of foil in the steamer basket and push down to form an edge so no oil leaks out. Rub the olive oil on both sides of the fish, season with salt and pepper as desired, place fish on the foil, fold the foil over the steamer basket. IF YOU DO NOT have a steamer basket that came with rice cooker, prepare the foil the same way, making sure there is raised sides all the way around to prevent the oil from going into the rice. At about 15 minutes into cooking the rice, add the steamer basket to the cooker or add the foil pouch directly on top of the rice, and let the cooker switch to Warm setting, a lot of this depends on your rice cooker and how long it takes to cook 1 cup of rice. If the fillets are think, put this in a few minutes earlier.