Turn on your oven to 175 °C (350 °F).
Slice leek into roundels.
Slice chili pepper on the diagonal. Take out any seed if you want less heat.
Wash and rinse spinach leaves.
Halve the cocktail tomatoes.
Prepare the two packages by cutting two aluminum foil squares about 30 x 30cm.
Layer the leek and spinach leaves at the bottom.
Place the fish fillet on top.
Sprinkle salt on top of fish.
Add halved tomatoes and sliced chili pepper on top of the fish.
And finish off by adding the shrimp.
Fold the aluminum squares to make a package. Closing it fully.
Put your fish packages in the middle of your preheated oven.
Cook for 17-20 minutes, depending on the thickness of your fish.
Use an oven thermometer to check that your fish is at 63 °C (145 °F).
Serve as is in the aluminum foil package.