1. In a large skillet, brown drumsticks in oil and butter.
2. Place in a 3 qt Dutch oveni.
3. Top with onion slices.
4. In the same skillet, heat tomatoes, bouillon and seasonings until bouillon is dissolved.
5. Pour over the drumsticks.
6. Cover and bake at 325 degrees for 2 hours, basting once or twice.
7. Add potatoes and zucchini.
8. Cover and bake for 20 minutes.
9. Remove drumsticks and vegetables to a serving dish and keep warm.
10. Combine the cornstarch and water until smooth; stir into tomato mixture.
11. Return to the oven, uncovered for 10-15 minutes or until slightly thickened.
12. Pour over drumsticks and vegetables.
13. Sprinkle with parsley.