Preheat the oven to 375 degrees F.
Cut the tops off the medium vine tomatoes and scoop out the flesh carefully, taking care not to pierce the bottoms. Season the insides with a pinch of sea salt.
In a small food processor, purée the reserved tomato flesh along with the garlic cloves.
Prepare a large skillet over medium-high heat. Sauté the small yellow onion in 2 tablespoons of olive oil until it becomes soft, around 4 minutes.
Add in the small zucchini and cook for an additional 3 minutes until it just begins to brown.
Stir in the arborio rice, cooking it until it becomes pearly white and toasty, around 2 minutes.
Carefully pour the puréed tomato mixture into the skillet, followed by the tomato paste. Let this simmer for about 2 minutes until the mixture thickens slightly.
Remove the skillet from heat and season with another teaspoon of sea salt and the optional freshly chopped parsley.
Arrange the hollowed tomatoes in a large casserole dish. Spoon the rice mixture into each tomato until just shy of full.
Replace the tops of the tomatoes and season generously with sea salt and pepper.
If you’re using the Yukon gold potato, place the wedges between the tomatoes for added texture.
Drizzle the vegetables with some extra olive oil and pour 1 cup of water around the tomatoes.
Bake in the preheated oven for 1 to 2 hours until the tomatoes are caramelized and the rice is al dente.
Serve your Greek Stuffed Tomatoes with Rice hot or at room temperature.