Cut the zucchini in 2-3 pieces. Hollow them carefully, leaving the bottoms so they resemble cups.
Finely chop the inside part of the zucchini: you will use it in the stuffing.
Heat the olive oil in a large frying pan or a skillet. Cook the onion and the garlic, until translucent. Add the carrots and the chopped inside part of the zucchini. Cook for 2-3 minutes, stirring continuously. Add the tomato passata and the rice. Cook between 5-10 minutes, until the mixture thickens. Season with salt, pepper and savory (or dill). Remove from heat and add the chopped parsley. Mix very well.
Arrange the zucchini in a large baking pan (10 x 12 inches or similar). Use a spoon to stuff the zucchini with the prepared stuffing.
Pour about 1 cup of water into the pan. Cover with aluminium foil and bake for about 40 minutes at 200º C/ 390º F. The meal is ready when the rice on top is soft. Don't remove the foil during the baking: the rice will be cooked by the water, evaporated from the bottom.