Peel and finely dice the onion and garlic. Wash thyme, shake dry, pluck off leaves and chop finely. Peel and wash the carrots, cut them into halves lengthwise and slice them.
Bring 3-4 l salted water (1 teaspoon salt per litre) to the boil. Heat oil in a pot. Sauté onion and garlic in it. Add carrots and thyme briefly. Deglaze with tomatoes, juice and 150 ml water, bring to the boil and stir in 1⁄4 tsp. salt. Cover and simmer for about 10 minutes.
Wash the salmon, dab dry and cut into slices. Cook pasta in boiling salted water according to package instructions.
Carefully mix salmon and capers together with the stock into the sauce. Let the salmon simmer in the sauce for about 2 minutes. Remove the pot from the stove. Season the sauce with salt, pepper and 1 pinch of sugar. Drain the noodles, put them back into the pot and carefully mix in the salmon sauce.