Preheat an oven. Place cherry tomatoes and fennel wedges in a large baking dish. Add extra virgin olive oil, smashed garlic, and oregano. Season with Kosher salt and crushed red pepper flakes, then transfer to the oven and cook.
Heat remaining olive oil in a saucepan over medium heat. When hot, add pastina. Add vegetable broth, raise the heat to medium-high, then cook until the pastina is tender.
In a medium bowl, mix chopped parsley, chopped toasted walnuts, chopped rosemary, garlic cloves, the zest of 1 lemon, Kosher salt. Stir in extra virgin olive oil, depending on how thick or thin you want the gremolata to be. Taste and adjust seasoning.
Divide into bowls, then top with some of the roasted tomatoes, fennel, and garlic (and flavored olive oil). Top with a generous spoonful of gremolata. Enjoy with shaved Pecorino Romano and lots of black pepper!