In a large pan, sear the diced onions for a couple of minutes until they start to become translucent.
Add the grated carrots to the skillet and fry for 2 minutes.
Toss in the chopped mushrooms and continue frying for a few more minutes until they release their moisture.
Add the rice to the veggie mix and fry for 2 more minutes, stirring.
Stir in a tablespoon of tomato sauce, then remove the pan from the heat.
Season the mixture with salt and pepper, and add a generous amount of chopped fresh dill. Mix everything well.
While the filling cools, prepare your peppers by cutting off the tops and removing the seeds and membranes.
Stuff each pepper with the rice mixture and set them aside.
In a large pan, heat a bit of oil and quickly fry each stuffed pepper for about a minute on each side.
Arrange the peppers in the pot, standing upright. If you like, place a slice of tomato on top of each pepper.
In a bowl, mix the tomato passata with the hot water, season with salt and pepper, and pour this sauce over the peppers. The liquid should almost cover them.
Bring the pot to a boil, then reduce the heat and let it simmer for about 40 minutes, or until the peppers are tender.
Serve hot with a dollop of sour cream/vegan alternative and an extra sprinkle of fresh dill on top.