A crunch at lunch: The crispy fish and chips with onion rings and sweet potato fries. [Photo by Pauline D. Loh / Shanghai Star]

The latest Blue Frog restaurant has finally opened along the eastern end of Huaihai Road, after a series of hiccups. Judith Huang books a table and tucks in.

The main attraction here has to be the extensive burger menu, with creatively named offerings bursting with imaginative flavors.

There is the signature Blue Frog Burger, served with lettuce, tomatoes, pickles and onions and a side of French fries, as well as the towering Mile High, which really lives up to its name with a double beef burger wrapped with bacon, cheddar cheese and spicy mayo.

Another must-have order is the side of sweet potato fries. For just 5 yuan, you can swap your French fries for these beauties, which are not only healthier but delicious as well. The sweet potato fries are long and slender, and very crunchy.

Their natural sweetness leaves you wanting more, and they are perfect on their own or dipped in ketchup. The Gourmet Burger, just past the mark at 108 yuan, combines avocado, chilli and lime cheddar cheese, mustard seed aioli, baby pepperoncini, Parma ham and a touch of sweet chilli jelly.

The burger, made with pure Australian beef, can be done to the diner's liking.

At medium rare, it was a hearty patty, full of texture and flavor, tender and juicy, and grilled to just the right amount of pink inside but cooked through.

The creaminess of the avocado blended with the cheese, while the Parma ham gave the burger a tinge of saltiness. The burger was pleasantly sweet with a spicy kick, thanks to the chilli jelly and mustard seed aioli.