To hollow out the kousa, trim off the top and use a zucchini core to slowly remove the inside of the squash. Be careful not to poke through the bottom or the sides. Once the squash is hallowed out, set aside.
In a medium bowl, combine beef, rinsed uncooked rice, salt, and pepper. Add half of the garlic (3 grated cloves) and half of the mint (1 tablespoon) to the meat mixture and combine.
Before you start stuffing the squash, place the tomato juice or tomato paste/water mixture in a large pot, and heat on medium high until boiling.
While the tomato juice is heating up, begin stuffing the kousa. Be careful to leave about 1 1/2 inch at the top which allows room for them to expand. If you have leftover meat mixture, simply roll them into little meatballs, and add to the tomato broth.
When the tomato juice has come to a boil, add the remaining mint (1 tablespoon) and garlic (3 grated cloves) as well as the lemon juice.
If you used tomato paste/water, add salt and pepper to the broth to taste.
Gently add in the stuffed kousa. Bring to a boil then turn to low and simmer for 35 minutes. The meatballs are the perfect way to see if the rice is fully cooked.