Heat the tablespoon of butter in a pan, add the onions and sweat a little. Add the rice and fry until translucent, deglaze with the bouillon and cover the rice with a low heat for about 15 minutes.
Melt 50 g butter in a second pan and fry the chopped large onion in it. Add the mushrooms, season with salt and pepper and cook the mushrooms covered for about 10 minutes. Remove the lid and let it cook until the liquid is almost boiled off. Add the cream and herbs, mix well and do not let boil anymore, just heat well. Season again with salt and pepper.
Form a ring on 4 plates with the rice and arrange the mushroom ragout in the middle of the rice ring.