Clean spinach, wash well. Peel onion and garlic, dice finely. Heat oil in a pot, fry onion and garlic, add spinach and 200 ml water. Season with salt and cover and let the spinach fall together for about 2 minutes.
drain in a sieve. Wash, clean, quarter and seed the tomatoes. Cut into small cubes. Squeeze and chop the spinach. Mix cream cheese with spinach and half of the diced tomatoes.
Season with salt and pepper. Clean the mushrooms, unscrewing the stems. Rub the mushrooms with kitchen paper. Pour cream cheese into the mushrooms. Put the mushrooms in a baking dish, add the remaining tomato cubes, pour on the stock.
Bake in the preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: level 3) for approx. 25 minutes. Simmer rice in 700 ml salt water for 18-20 minutes until all the water is absorbed. Serve mushrooms with the rice.
Garnish with basil.