How to Make It
Cook pasta according to package directions. Drain and rinse pasta under cold running water; drain well.
While pasta cooks, stir together feta, buttermilk, mayonnaise, hot sauce, lemon zest and juice, salt, garlic, and black pepper in a medium bowl.
Transfer pasta to a large serving bowl. Add buttermilk dressing, torn herbs, celery, tomatoes, red onion, and sunflower seeds, and toss well.
Stir 1 tablespoon plain whole-milk Greek yogurt into 7 tablespoons milk as a substitute for buttermilk in this recipe.