Clean and slice the mushrooms. Peel and chop the onion. Wash the tomato, dab dry, quarter and remove the seeds. Cut the tomato quarters into small cubes. Wash the thyme, dab dry and pluck the leaves, except for something to garnish.
Heat the oil in a pan and fry the medallion on each side for about 2 minutes. Season medallion with salt and pepper. Roast the toast bread and arrange the fillet on top. Pour oil from the pan, melt some fat in the hot pan and fry the onion in it. Add mushrooms, fry lightly and season with salt and pepper. Pour on cream, add tomatoes and thyme and bring to the boil. Cut gorgonzola into pieces and stir into the cream sauce. Pour immediately over the medallion. Bake in the preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: level 4) for about 8 minutes, or gratinate under the preheated grill for 4-5 minutes.
Add mushrooms, fry lightly and season with salt and pepper. Pour on cream, add tomatoes and thyme and bring to the boil. Cut gorgonzola into pieces and stir into the cream sauce. Pour immediately over the medallion. Bake in the preheated oven (electric cooker: 225 °C/ convection oven: 200 °C/ gas: level 4) for about 8 minutes, or gratinate under the preheated grill for 4-5 minutes. Arrange on a plate with some salad and serve immediately garnished with thyme