Boil pasta according to instructions on the package. Drain and rinse. Heat pan, and then add the olive oil. Once oil shimmers, add minced garlic and diced shallots. Season with salt and pepper. Cook, stirring occasionally, until garlic is golden and shallots have caramelized. Now, add zucchini, season with salt and pepper, and cook until tender and translucent. Add halved grape tomatoes and cook until they’ve softened. Add pasta and season with salt, pepper, and red pepper flakes. Prepare ingredients for the lemon-tahini sauce by whisking all of the ingredients together - you may have to add a tbsp or two of extra water in case the mixture seizes. You want it to be creamy and smooth. Season to taste. Pour sauce over the pasta and vegetables, stirring to combine. Season with salt and pepper, a squeeze of fresh lemon juice, and serve immediately!