Cut the leek into fine rings. If not already bought (e.g. frozen), remove the scampi from the shell except for the tails. Make an incision lengthways on the curved side and remove the intestine.
Chop the garlic and parsley, cut the tomatoes in half. Fry the leek in hot olive oil for 2 minutes, season with salt and pepper. Take out and keep warm.
Now cook the spaghetti in salted water according to the instructions on the packet. Then sauté the garlic in the frying oil and add the scampi. Fry for about 4 minutes, turning. Season with salt and pepper. Take out and keep warm as well.
Now add the tomatoes to the frying oil, turn the stove on briefly, then deglaze with the lemon juice and whipped cream and sprinkle with parsley.