Red Dragon is a Cheddar-type cheese from Wales made with brown ale and mustard seeds. It is sometimes also called Y-Fenni. Red Dragon is a relatively new. Now, they are creating other fine cheeses such as Red Dragon, also known as Y- Fenni. This smooth, firm, tasty cheddar is made with Welsh brown ale and. Made with Welsh brown ale and whole mustard seeds, Red Dragon mustard seed and ale cheddar is tangy and buttery, perfect for sandwiches or melted on.