Wash and cut stems from zucchini. Carefully scoop seeds from centre using a spoon or special corer, leaving a thin shell.
Rinse shells and soak in cold, salted water for a 1/2 hour.
Mix together meat, rice, 1 tsp salt, pepper, cinnamon, allspice and melted butter together.
Stuff loosely with meat mixture to 1/2" from top of shell to allow for expansion of rice.
Place stuffed shells in a deep pot. Add tomatoes, water, salt, garlic and mint. Add water to completely cover shells.
Bring to a boil. Reduce heat to low and simmer for 40-50 minutes.