Chop the onion and the garlic cloves finely.

Heat the oil in a large pan and cook the onions until translucent. Add the garlic, stir it shortly in the pan. Add the canned tomatoes, crush them if they are whole. Half fill the empty can with water and give it to the pan.

Add the tomato paste, herbs, bay leaves, sugar salt, and pepper, stir very well.

Bring to a boil and cook on a medium-high flame for about 15 minutes. Turn the heat down and continue cooking the tomato sauce, stirring occasionally, for about 15 minutes or until it thickens slightly. Adjust the taste with salt, pepper, and a little more sugar, if necessary.

Remove the bay leaves from the sauce and puree the sauce with a blender until smooth.

Cut the top of the peppers and carefully remove the seeds. Bring a large pot of water to a boil, add a little salt and cook the peppers for 2 minutes. Drain well.

Clean the vegetables. Cut the carrot and the zucchini into thin sticks and slice the mushrooms and the onion.

Heat the oil in a large pan, add the vegetables, sprinkle them with the sugar and cook them, stirring often, for about 7-8 minutes or until most of the liquid released by the mushrooms is gone. Add salt and pepper to taste. Fill the peppers with the vegetable filling.

Pour the tomato sauce and vegetable broth in a pot large enough to hold the peppers. Bring to a simmer and add the tomato paste. Stir well, add more salt and pepper if necessary, then place the peppers in the sauce. Cover, turn the heat down to low and cook the peppers, turning on the other side after half of the cooking time, for about 20 minutes or until soft but not mushy. Remove the lid from the pot and cook the peppers for 5 minutes more, allowing the sauce to thicken slightly.

Sprinkle with lots of fresh parsley and serve with mashed potatoes.