Tear out 4 pieces of aluminum foil or parchment paper, enough to hold and seal fish in a parcel.
Cut fish fillets into half and divide among foil squares, placing them in the middle.
Top each with tomatoes, herbs and a few slices of lemon.
Season with salt and pepper then drizzle with olive oil.
Fold sides of the foil together to form a parcel.
Make sure the parcels are well sealed. Steam parcels in a steamer for 5-7 minutes. Alternatively, you can bake them in the oven at 400°F/200°C for 10-12 minutes.