Learn more about how to make this dish in my video, here! Lebanese koosa is a light green version of zucchini, or summer squash. Hollow the koosa out using a koosa corer (or, if you don't have the Lebanese tool, a zucchini corer will work). The recipe is very easily halved or doubled. This recipe is vegetarian, vegan (leave off the labneh), gluten-free, and tastes just as wonderful as a meat-lover's koosa!
First, trim the koosa. Cut the stem end of the koosa low enough to remove any bend in the koosa and to create a flat top. Slice the very tip of the round end off as well.
Hollow out the koosa using a Lebanese koosa corer or zucchini corer, leaving about 1/4-inch perimeter inside the koosa (it's quite hollow; be careful not to make the interior too thick). Don't worry if you poke through a koosa, it can still be used! Discard the cores or save for another use (the Lebanese like to drain the cores and cook them with eggs, ijjeh).
In a medium bowl, rinse the rice and pour off the water. Stir in the tomato, scallions, onion, parsley, and mint. Season with cinnamon, salt, and pepper and stir well.
Fill the koosa with the rice mixture, spooning it into the hollowed squash and gently pushing the filling into the cavity. Be sure to leave at least 1/4-inch headroom with no filling at the top of the koosa, otherwise once the rice cooks and expands it will fall out of the koosa.
Place the stuffed koosa in a large pot, leaning the koosa against one another on an angle. Tuck in the garlic cloves and onion slices. Pour the tomato juice over all, then fill the container with some water and pour that over almost to cover the koosa. Season the broth with salt and pepper.
Cover the pot and bring to a boil over medium high heat. Reduce to medium low and simmer for about one hour, or until the koosa is tender.
Transfer the koosa to a serving dish and reduce the sauce a bit to thicken it. You can add tomato paste as well (loosen it with the sauce before adding to the pot). Increase the heat to bring the sauce to a boil, and boil for about 10 minutes, or until the sauce thickens and gains some body. Take care not to scorch the bottom of the pan or to over-reduce the tomato sauce here. Unlike pasta sauce, In the end this sauce is still quite liquid, which is what we want.
Ladle the tomato sauce over the koosa. To serve the koosa, cut the top side open lengthwise and spoon the sauce over. A dollop of labneh is delicious served on top!