In 6 qt. kettle, put zucchini, onion, tomatoes, parsley, salt, pepper, basil, thyme, and 1/2 cup water. Boil 10 - 15 minutes. Vegetables should be tender but firm.
Reduce heat to simmer. Add corn, lemon juice, and Tobasoc sauce. Dissolve chicken bouillon cubes in boiling water and add. In separate pan, melt butter and blend in flour to make a roux. Using a whisk, gradually stir in milk. When mixture thickens, add cheddar and parmesan cheeses. Stirring constantly, add milk - cheese mixture to the vegetable pot.