Slice the zucchinis lengthwise and take a small spoon or ice cream scoop and ‘gut’ out the inside of the zucchinis. Place in a glass baking dish and brush the zucchini halves with olive oil.
Bake for 20-25 minutes, or until the zucchinis are soft (cook time may be dependent on the size of your zucchinis).
While zucchinis are in the oven, add the ground beef and chopped onions in to a medium saucepan and cook over medium-high heat until beef is browned and onions are translucent and then add the lemon juice, spices, tahini and water Stir until well combined and add more water if the mixture is too thick.
Once the zucchinis are cooked, add the beef mixture to the hollowed insides and place back in the oven for around 5 minutes to heat throughout.