Like Parmesan, Gorgonzola is not suitable for vegetarians. This is due to the animal rennet used while making it. Because Gorgonzola is DOC listed, it has to be made in this traditional way; otherwise it cannot be called Gorgonzola.
Gorgonzola is often used in ‘vegetarian’ meals in restaurants, so check with the waiter/waitress if the meal is actually made from Gorgonzola, or a similar type of cheese.
Many widely available Roqueforts, are also not suitable for vegetarians. Since it is AOC listed (the French equivalent of DOC), the addition of rennet must occur within 48 hours of milking. However, it does not specifically state that this rennet must be animal rennet, and so it is possible that there might be some vegetarian versions of Roquefort. My advice would be to check the label. If you do come across a vegetarian Roquefort, please get in touch and let me know!
There are plenty of lovely and widely available creamy blue cheeses that can be used as substitutes that are just as great for stirring into pasta or spreading on crackers. Luckily, for us Brits, almost all Stilton cheeses are vegetarian.
Particularly good alternatives that a commonly available throughout the UK and have similar creamy textures to Gorgonzola and Roquefort include: