Wash the zucchini and remove the top with a sharp knife. Use a spoon to scrape out the pulp into a bowl. For this recipe, we are going to use only half of the zucchini pulp. The rest can be added to a pasta sauce or a vegetable soup, along with the zucchini tops.

Finely chop half of the zucchini pulp. Add two tablespoons of extra virgin olive oil, a whole clove of garlic, the chopped pulp, and a pinch of salt to a pan over medium-low heat. Sauté for about 10 minutes. At first the zucchini will release some water, then it will cook down into a soft and tasty mush.

Transfer the cooked pulp into a bowl and mix it with the grated Parmigiano Reggiano, diced fresh pecorino, beaten egg, tuna, and breadcrumbs. Mix thoroughly with a fork until homogeneous. Season with salt, if needed.

Stuff the zucchini with the tuna filling, pressing it with a spoon, taking care not to break them.

Pour four tablespoons of extra virgin olive oil in a thick-bottomed pan and add the zucchini. Add the halved cherry tomatoes and the thinly sliced onion.

Cook the zucchini over medium heat for about 5 minutes. When they start to sizzle, pour in the white wine and reduce until almost all the wine has been absorbed, for about 5 more minutes.

Pour in the vegetable stock or water, cover with a lid, reduce heat to low, and cook for about 35 minutes, until the zucchini are soft. Check the zucchini often, spooning some of the cooking liquid from the pan over the stuffing.

Serve the stuffed zucchini immediately, while hot. They're also good the next day, reheated for a few minutes.