Saute fine diced onions in olive oil in a large sauce pot until translucent. Add the minced garlic and the oregno. Add the tomato sauce and the fresh chopped thyme. Stir well and add the bay leaf. Bring to a boil, stirring often, and reduce to a simmer. Cook for one hour. Add the tomato paste, ensuring that it is completely folded into the tomato sauce. Add the fresh chopped basil and simmer for 10 more minutes. Remove the bay leaf and the sauce is ready for service.