Clean the spinach, wash thoroughly and drain. Peel onion and garlic and dice finely. Roast pine nuts in a pan without fat until golden brown. Remove from the pan and heat oil in it.
Fry the onion, garlic and spinach in it until the spinach has collapsed. Season with salt and pepper. Heat 1/8 litre water, stir in sauce powder and bring to the boil. Stir in the fat little by little.
Fold in spinach and pine nuts. Wash the tomatoes, cut a lid off each and hollow out the tomatoes with a teaspoon. Fill the spinach and sauce into the tomatoes and place the lids on top. Put the tomatoes on an oiled baking tray and bake in the preheated oven (electric cooker: 225 ° C/ gas: level 4) for about 20 minutes.