Preheat oven to 350Wash, core tomatoes and quarter tomatoes. Place them in cast iron pan or roaster pan and drizzle with oil and salt. Place the pan in the oven and cook until skins of tomatoes come off easily (about 10-15 minutes).
While that is cooking, saute garlic in oil.
Peel the onion and cut in half, place it in the food processor and blend until chopped in small pieces. Add the onions to the garlic, and season, cook until done.
When the tomatoes are finished, peel the skins off and discard. Add the tomatoes to the pot of onions and garlic. Using the hand blender, blend until soup is smooth and creamy. Taste for salt, and add more if needed. Serves 2-3