What is the primary flavor profile of "szechuan peppercorns," and how are they used in cooking?

Szechuan peppercorns are a unique spice from the Sichuan province known for their distinctive flavor profile, which includes a citrusy, slightly lemony taste and a numbing sensation on the palate. Unlike black pepper, they do not add heat but rather create a tingling sensation that enhances the overall flavor of dishes. They are often used in Sichuan cuisine in combination with chili peppers to create a complex, spicy, and numbing flavor in dishes like Kung Pao Chicken and Mapo Tofu.