The Portobello mushroom is a large, mature variety of the Agaricus bisporus species, which also includes the common white and cremini mushrooms. Known for its meaty texture and rich flavor, it is often used as a meat substitute in various dishes, making it popular among vegetarians and vegans. Portobello mushrooms are typically brown and can grow up to six inches in diameter. They are versatile in cooking, suitable for grilling, roasting, or stuffing. Nutritionally, they are low in calories and provide essential nutrients like fiber, potassium, and antioxidants, contributing to a healthy diet.