There are two different preparations of zucchini here: spiralized and grilled. If you don't have a grill, you can just roast your zucchini or sauté them in a pan, but if you don't have a spiralizer, you're going to want one just for this. It's an amazing kitchen tool, one you can have the most fun with.
Zucchini slices: Cut 1 zucchini into ¼-inch rounds, place in a bowl, and toss with 1 tablespoon olive oil and a pinch of salt. Heat a grill pan to medium-high; cook zucchini until there’s a slight char on either side. Set aside.
Zucchini "noodles": Trim the ends off the remaining zucchinis, cut them in half vertically, and use a spiralizer to make long ribbons, yielding 8 cups of zucchini "noodles." Set aside.
Sauce: In a skillet over medium heat, add remaining 4 tablespoons of olive oil and the garlic. Once the garlic is fragrant (about 1 minute), turn the heat to low. Add the labneh and water; stir slowly, incorporating everything thoroughly. Season with a few pinches of salt, and allow mixture to slowly cook. Chop herbs and set aside. Meanwhile, cook the pasta in salted, boiling water to al dente (should take less than 3 minutes). Drain and add to the sauce, along with the zucchini noodles and chopped herbs; salt to taste. Mix well so the zucchini noodles and pasta are evenly sauced.
Assemble the dish: Add the zucchini and pasta noodles to a serving dish; arrange the grilled zucchini slices around the edge. Finish with lemon juice, a bit of salt, and a mint sprig or two. Serve immediately.