In a small skillet, saute onion in oil until tender. Add garlic; cook 1 minute longer., Transfer to a 1-1/2- or 2-qt. slow cooker. Stir in the clams, tomatoes, tomato paste, parsley, bay leaf, sugar, basil and thyme., Cover and cook on low until heated through, 3-4 hours. Discard bay leaf. If desired, sprinkle with additional parsley. Serve with linguine. Freeze option: Omit additional parsley. Cool before placing in a freezer container. Cover and freeze for up to 3 months. To use, thaw in the refrigerator overnight. Place in a large saucepan; heat through, stirring occasionally. Serve with linguine and, if desired, minced parsley.