Lightly coat bottom of a large saucepan or Dutch oven with oil. Add onion and cook over low heat, stirring occasionally, until soft, about 5 minutes. Add garlic and cook, stirring, for 1 minute. Add Tofurky or sausages and cook according to package instructions Puree the diced tomatoes. Add tomatoes, purée, dried basil, oregano, salt and pepper. Add red pepper flakes and fennel or anise Bring sauce to a simmer. Continue to simmer over low heat, stirring occasionally, until tomatoes have dissolved into a thick sauce, about 30 to 45 minutes. If using fresh basil, add it at the end of cooking time