Defrost the frozen shrimps. Peel and finely chop the onions and garlic. Wash parsley, shake dry and chop finely.
Heat the oil. Sauté onion and garlic until transparent. Stir in tomatoes, juice and parsley. Crush the tomatoes. Bring to the boil and simmer for about 5 minutes. Season with salt and pepper.
Shrimps, up to the tips of their tails from the shell. Make a longitudinal incision in the back and remove the dark intestine. Wash the shrimps, pat dry and put them on 6 oven-proof deep plates or in 1 casserole dish.
Pour tomato sauce over it. Dice the cheese and sprinkle over it.
Bake in the preheated oven (electric oven: 175 °C/circulating air: 150 °C/gas: level 2) for 10-15 minutes.