Hunan chicken and Szechuan chicken are both popular dishes in Chinese-American cooking involving chicken and a various vegetables. The key difference between Hunan and Szechuan chicken (Sichuan) is in the sauce. Both are spicy but the heat from Hunan spicy chicken comes from a mix of fresh chili peppers stir-fried with the chicken. Szechuan chickens' spiciness comes from Szechuan peppercorns and dried chiles.