• Rinse and drain rice in colander, transfer to a bowl and cover with water. Set aside to soak for 30 minutes.

Prepare zucchini

• Trim the ends of the zucchini and set aside. Starting from the one cut end, use an apple or zucchini corer and carefully insert, twist and scoop out zucchini flesh (save for other use), leaving about 1/3-inch ring.
• Trim ends from tomato and remove all seeds. Cut flesh into circle pieces to plug the ends of the zucchini. Set aside.

Stuffing

• In a large skillet over medium-high heat, heat olive oil until shimmering and add onion. Cook 3 minutes, then add ground beef, breaking up the meat with a wooden spoon. Add the salt, Lebanese 7 spice, pepper and chopped mint leaves. Sauté until browned, about 8 minutes, stirring often. Remove from the heat and set aside.
• Drain the rice and add to ground beef mixture, stirring to combine.

Sauce

• In a large, deep pot or Dutch oven heat the oil over medium heat. Stir in garlic and saute for 2 minutes. Add the passata or pureed tomatoes and chicken stock (or water). Bring to boil, turn heat to low and simmer while you stuff the zucchini.

Assembly

• Insert a tomato piece into the end on one side of a cored zucchini, acting as a plug. Then use your hands to stuff the zucchini with meat/rice filling, leaving about an 1/4 inch near the top for the cooked rice/meat mixture to expand. Plug the top with several mint leaves or another tomato plug. Repeat with all zucchini.
• Arrange the stuffed squash cut side up in the large pot or lay down and stack. If tomato broth doesn't cover the zucchini add just enough water to cover.
• Bring to a boil over high heat, then reduce to low. Simmer, covered until rice is cooked through and squash is tender, about 45 minutes.
• Carefully remove stuffed zucchini from pot. Stir through lemon juice and serve tomato sauce poured over Kousa Mahshi.