Preheat the oven to 350°F and line a baking sheet with aluminum foil or parchment paper.

Gently wash the mushrooms to remove any debris and carefully snap off the stems (save them for later). Use the side of a spoon to scrape out the gills of the mushroom caps, taking care to keep the mushrooms intact.

Use a brush or your hands to coat the outer sides and edges of the mushrooms with about 1 tablespoon of olive oil. Place on the prepared baking sheet with the hollow sides facing up. Sprinkle with about ¼ teaspoon of salt and ½ teaspoon of the Italian seasoning. Place a tomato slice on top of each mushroom cap. Set aside.

Coarsely chop the mushroom stems. In a medium skillet on medium-low heat, add 2 tablespoons of extra virgin olive oil. Once the oil begins to shimmer, add the garlic and stir constantly for 30 seconds before adding the chopped mushroom stems, spinach, and green onions. Add the remaining 1 teaspoon of salt. Cook until the spinach is wilted, about 5 minutes. Turn off the heat and set aside.

In a small mixing bowl, mix together the ricotta cheese and remaining 1 ½ teaspoons of Italian seasoning. Add the sautéed vegetables and stir to combine. Distribute the mixture evenly among each mushroom. Bake for 15 minutes.

After the time is up, remove from the oven, top with the breadcrumbs and a drizzle of extra virgin olive oil. Return to the oven and broil on low until the tops are golden brown, about 3 to 5 minutes. Let cool for 5 minutes before serving.