Choose a large potato with an even healthy skin and wash it well with a vegetable brush. Cut it in quarters.
Boil the potato quarters for about 12 minutes. Be careful not to make them too soft otherwise you will break the skin.
Drain the water away and let the potato quarters cool down for a few minutes before you scoop the flesh away using a sharp knife or a melon baller. Try to leave a skin no more thick than 1cm (1/2inch) as potato flesh is full of carbohydrates and that means calories!
Oil your oven dish using oil spray and place your skins on the one end of the oven dish.
Cut the tomato finely and do the same with the coriander. Mix these together and add pinch of salt and black pepper. Pile these over your four potato skins and sprinkle the grated cheese over that.
Cook in the oven for 15-20 mins until skin is slightly crispy and the cheese has obtained a nice brownish colour.
On the other end of your oven dish you can place a tinfoil big enough to take 1-2 cod fillets.
First slightly oil the tinfoil and then place the frozen or fresh cod on that. Sprinkle with salt and black pepper and place 2-3 lemon rings and sprig of thyme over them.
Close the tinfoil like and envelope and cook in oven 200°C for 20-25mins.