Preheat oven to 400°F. Coat a rimmed baking sheet with 1 tablespoon olive oil. Clean the tomatoes. Cut the top off each tomato and reserve. Scoop out the insides and reserve. Place the hollow tomatoes in baking dish and sprinkle with salt. Fry the onion and garlic in 1 tbsp olive oil in a large skillet for about 5 minutes. Add the ground pork until the meat just loses its pink color, and season with pepper. Add the reserved tomato flesh and cook until the liquids evaporate, about 10 minutes. (Alternately, to go faster, you can cook the tomato separately at the same time as the onions.) Transfer to a bowl and add the quinoa, parmesan, thyme and parsley. Spoon into the tomato cups and place the tops back on. Place in dish and drizzle olive oil over the tops. Place mushrooms all around. Bake about 45min.