Drain the tomatoes and dab with kitchen paper. Cut tomatoes into wide strips. Peel and finely chop the onion. Clean the mushrooms, wash them briefly and cut into thick slices.
Cook the pasta in plenty of boiling salted water according to the instructions on the packet until al dente. Heat the oil in a pan and fry the mushrooms for about 3 minutes. Add onion and tomatoes and fry briefly.
Pour on cream, stir in stock and bring to the boil. Season to taste with salt, pepper and thyme. Simmer at low heat for about 2 minutes.
Wash parsley, shake dry and chop finely. Drain the pasta, let it drain and put it back into the pot. Mix immediately with the mushroom sauce and parsley and serve.