Clean, wash and cut the leek into 12 cm long pieces. Cut each piece in half lengthwise. Blanch in boiling salted water for 2-3 minutes. Drain, rinse with cold water, drain.
Wash the salmon, dab dry and cut into cubes. Lemons wash, dab dry. Squeeze 1/2 lemon. Sprinkle salmon with juice. Cut remaining lemons into pieces. Wash and clean the tomatoes.
Wrap each salmon cube with one leek strip. Put them alternately with lemon and tomato on 8 skewers. Remove seeds from remaining tomatoes and cut into small cubes. Peel, halve and finely dice the shallot.
Fry in 1 tablespoon of oil. Add the strained tomatoes and cream and simmer at a mild heat for about 5 minutes. Cook pasta in boiling salted water for 6-8 minutes. Heat 2 tablespoons of oil in a large pan.
Fry the skewers for 2-3 minutes on each side. Season with salt and pepper. Season sauce with salt, pepper and sugar. Stir in diced tomatoes. Drain the pasta and mix with the remaining leek strips and sauce.
Arrange the noodles on skewers. Serve garnished with thyme.