Preheat the oven to 400 °F
In a covered skillet, cook the chopped zucchini and minced garlic together over medium-high heat until the zucchini is soft and most of the moisture has cooked out. Transfer the zucchini and garlic to a plate.
Spray some nonstick spray in the same skillet and cook the beef over medium-high heat until no longer pink.
Add the zucchini, the tomato sauce, the spices, salt and minced olives, bring the mixture to a boil over medium-high heat then turn the heat all the way down to low and let it simmer about 5 minutes until all the liquid has been absorbed.
Spray a baking dish with nonstick spray and arrange the tacos inside
Spoon the taco filling into the taco shells
Grate the cheddar cheese on top of the tacos, making sure each taco gets an equal amount of cheese.
Put it in the oven for about 15 minutes, until the cheese is melted and the tacos are heated through.
Everyone gets ¼ cup of Greek yogurt and ¼ cup of salsa with their tacos