Cook the rice according to the instructions on the packet.
In the meantime, clean the mushrooms and cut them into leaves, finely chop the onions, parsley and garlic.
Heat the butter in a pan and sauté the onions and garlic until translucent. Add the mushrooms and sauté briefly. Sprinkle the flour on top and deglaze with the stock. Stir well so that no lumps form. Let the ragout simmer for about 20 to 30 minutes, add more liquid if necessary and then stir in the cream. Season with salt and pepper and sprinkle with fresh parsley.
Arrange the rice on a plate, pour the mushroom ragout over it and serve.